There are many different kinds of physical and mental yoga practice under different paths and lineages in the path of yoga.
It's not about creating competition or comparison among the different paths or lineages, of which path or lineage is better than the others, or the best among all, or the easiest one, or the safest one, or the most difficult and challenging one, or the most popular one, or the most effective and beneficial one, or the most spiritual one, and etc, but it's about the availability of many different varieties/tastes to 'suit' and 'interest/attract' the many different worldly passionate egoistic restless minds that are functioning under the veil of ignorance, the idea of 'I', egoism, impurities, and restlessness, that come under many different traits, personalities, characteristics, backgrounds, conditions, thinking, beliefs, ideas, values, interests, and desires, to be devoting some, or most, or even all of their life existence, attention, effort, and energy, onto performing one, or some, or all kinds of physical and mental yoga practice, persistently and regularly.
More importantly, by devoting some, or most, or all of one's life existence, attention, effort, and energy, into performing persistent and regular physical and mental yoga practice, is not about achieving perfection in the yoga practice(s) at all.
Regardless of whether the body and/or mind can or cannot achieve certain degrees of 'physical/mental/spiritual improvement/achievement', or even 'perfection in all kinds of practice', in the respective yoga practice(s) or disciplines, it doesn't determine or guarantee that whether the mind is, or will be liberated from ignorance and the by-products of ignorance, or not.
What are the physical condition/ability/limitation or the state of the mind, is not important at all. Regardless of what are the physical condition/ability/limitation or the state of the mind, as well as what are the result, or the fruit, or the effect/benefit of the different yoga practice(s), all are impermanent.
What is impermanent, that is momentary, that is conditional, that is the effect of a cause, that will change, and pass away, is not 'real'. It's not the goal of the practice.
If so, why is it still so important to devote the life existence (time), attention, effort, and energy into performing some kind of yoga practice(s)?
It's merely about moving the mind away from (the influence/distraction/attachment/identification of) all kinds of worldly restless passionate egoistic ideas, beliefs, affairs, attachments, identifications, aspirations, inspirations, desires, intentions, ties, connections, interactions, activities, duties, and responsibilities (as much as possible), physically and mentally, during those moments when the mind is devoting or immersing into certain kind of physical and mental yoga practice that is all about disciplining, purifying, and quieting the restless modification of the mind, while channeling the life existence, attention, effort and energy onto 'something' such as 'the teachings and practice of yoga' that is about thinning-out/weakening/eradicating the veil of ignorance, the idea of 'I', egoism, impurities and restlessness, that is about developing openness and kindness, that is about realizing compassion and wisdom, that is about right discrimination (wisdom/correct understanding/non-separateness/oneness/selflessness/impermanence/simplicity/desirelessness) that leads to non-discrimination/non-craving/non-aversion towards the many different selfless impermanent qualities of names and forms, that allows the mind to be opened (not being conditioned or influenced by worldly passionate egoistic ideas, thinking, beliefs, values and practice), that allows the mind to attain direct experience or realization towards the truth of selflessness and impermanence, and hence, be free from ignorance and the by-products of ignorance, or suffering, that allows the mind to be resting in unconditional peace.
However, not all or any kinds of physical and mental activities that require certain amount of attention, effort, and energy, will be leading the mind towards the annihilation of ignorance and suffering, or unconditional peace.
The many minds can also be devoting most, or all of their life existence, attention, effort, and energy onto 'something that attracts their interest' or 'some kind of activity, practice or training', that significantly improve their intelligence, creativity, knowledge, ability, and skill in that particular thing/activity/practice/subject, that give rise to many different 'inspirational' ideas, productivity and creativity, but then, it's not necessarily something that promotes peace and harmony in oneself and/or others and the world of diversities that doesn't belong to anyone or anything, that could be creating many ideas, products, or activities that promote damage, destruction, exploitation, unrest, and disharmony in the world instead, either intentionally or unintentionally, because the minds are still very much functioning under the influence of ignorance, the idea of 'I', egoism, impurities, and restlessness.
It's the right attention, right effort, and right action/practice, that is about developing/empowering/activating the process of the thinning-out/weakening/annihilation of ignorance, the idea of 'I', egoism, impurities, and restlessness, that will lead to right discrimination, or dispassion, or correct understanding, or wisdom, or unconditional peace, or promoting peace and harmony in the world of diversities that doesn't belong to anyone or anything. That is nothing to do with the impermanent physical and mental condition/ability/limitation, or the result/fruit/effect/benefit of the different physical and mental yoga practice.
All kinds of momentary effects of rendering the mind to be focus, calm and quiet, is merely preparing the mind to be able to have a few moments of precious clear reflection to be reflecting upon the truth of selflessness and impermanence, that allows the mind to go beyond the impermanent physical and mental condition/ability/limitation and the side-effects of the yoga practice, but it doesn't guarantee the annihilation of ignorance and suffering, if without integrating/activating the process of thinning-out of the veil of ignorance and its by-products, and if the mind doesn't reflect/inquire upon the truth of selflessness and impermanence, but only enjoying, attaching towards, and identifying with the acquired state of attentiveness, calmness, and quietness via the yoga practice that is impermanent, that is not the means of the yoga practice.
One can be devoting all of one's life existence, attention, effort, and energy into performing some kind of physical and mental yoga practice regularly, of certain path or lineage, while attaining and enjoying all kinds of momentary agreeable physical and mental health and fitness effects or benefits from the devoted persistent regular yoga practice, however, if without integrating/activating the eradication of ignorance, the idea of 'I', egoism, impurities, and restlessness, but instead, all that are being empowered while performing all those physical and mental yoga practice(s), then the mind will still be functioning under the influence of ignorance and its by-products, even after many years of 'practicing yoga' and/or 'teaching yoga'. There's neither right nor wrong. At least, during the moments of their existence, attention, effort, and energy that was being spent on performing the yoga practice, the minds are not performing any unwholesome harmful activities that would harm themselves and/or others and the world.
Such as, in certain physically demanding and mentally challenging type of yoga asana practice under particular lineage, that requires intense devotion or discipline of a few hours per day for six days a week of persistent practice, or else, the body and mind won't be able to develop and have the required physical and mental skill, stamina, strength and flexibility to be performing the full routine of such physically demanding type of yoga asana practice. The main purpose of such intense yoga asana practice, is all about to move the mind away from worldly passionate egoistic affairs and activities as much as possible, as well as to be breaking the ego, to allow the mind to see the truth of selflessness and impermanence, through engaging in such attention, effort and energy consuming practice.
As no matter how much time, attention, and effort has been spent into maintaining and enhancing the condition/ability of the physical body and the modification of the mind, that no matter how skillful, fit, strong, flexible, and healthy that the physical body can become, and no matter how good, positive, successful, accomplished, and meaningful is the mind feels about itself and everything, the body and mind is still a selfless impermanent limited and conditional adjunct, where all the effects/benefits of well-developed/enhanced skill, stamina, strength, flexibility, and health condition, are all impermanent. And no matter how skillful, fit, strong, flexible, and healthy is the physical body, or how knowledgeable, intelligent, good, or calm is the state of the mind, and no matter what kind of super extraordinary physical or mental experiences that the mind is experiencing before/during/after the devoted persistent regular practice, it cannot escape or change the truth of selflessness and impermanence.
If the mind doesn't understand this, where it thinks and believes that it's about achieving 'certain result' or 'perfection' in the yoga asana practice or some other yoga practice, then it will try to achieve certain result or perfection in the yoga asana practice or some other yoga practice, by continuously keep pushing the body and mind beyond its limitation that would give rise to unnecessary injuries or damages to the body and mind, empowering ignorance and egoism, which is the opposite of what yoga is about.
So what, if the body can stay in the headstand, or handstand, or any position, or holding the breath for a prolonged period of time until the energy or strength is depleted completely, or until the body can't hold the position or the breath any longer after holding it for a prolonged period of time. Some even acknowledged and identified themselves as the national or world record time holder for holding the breath or for holding such and such position for how many minutes, or hours, or days. It only indicates that the mind is still very much under the influence of ignorance for trying to challenge the body and mind beyond its limitation in order to achieve certain result or perfection. But, if the mind can start to see the truth of selflessness and impermanence after engaging in such action/activity/practice, then it served the purpose of performing the challenging intense yoga asana practice, or holding the breath (pranayama).
Without renunciation and dispassion (towards the mind perception of selfless impermanent life existence and the world of names and forms, of all kinds of ideas, affairs, objects, ties, connections, relationships, activities, desires, aspirations, inspirations, attachments, identifications, anticipations, expectations, achievements, conditions and situations), all kind of devoted, persistent and regular physical and mental yoga practice doesn't lead to the liberation from ignorance and the suffering deriving from ignorance, but only give rise to some momentary pleasant or unpleasant side-effects, that are also impermanent, that are still within the manifestation of MAYA.
If all minds (human beings) spent their entire existence, attention, effort, and energy onto performing some kind of yoga practice where this selfless impermanent life existence of a body and mind is mainly for the purpose of conquering one's restless modification of the mind to be inquiring the truth of everything, (or without the need of performing any kind of yoga practice, but merely living a life of simplicity and desirelessness,) the world will be so peaceful devoid of actions and consequences of actions deriving from human beings with the mind functioning under the influence of ignorance, the idea of 'I', egoism, impurities and restlessness, where the minds that are occupying the world are purely focusing on their yoga practice, or on their simple basic way of living, while only need to spend minimal attention, effort and energy into finding enough basic needs for looking after daily life maintenance, devoid of worldly passionate egoistic greedy desires for attaining excessive accumulation and hoarding of wealth and objects beyond the basic needs for life maintenance in the present moment, to be enjoying all kinds of unnecessary physical, mental, material, sensual, and leisure enjoyments, being inspired to be having great vision, aspiration, and ambition to be selfish and prideful towards developing and empowering a personal and group identity, to be discriminating, interfering with, intimidating, and conquering the others, to be occupying, possessing, and controlling the world to be and not to be in certain way, to be achieving higher and higher accomplishments and enjoyments by exploiting all and everything to the maximum, to be gratifying one's greedy endless desires.
The worldly passionate egoistic restless minds that were being conditioned by worldly passionate egoistic ideas, thinking, beliefs, values, practices, behaviors, actions and reactions, to live life and to think/believe/reason/judge/understand/desire/behave/act/react in certain way, will see 'this' as a form of 'non-development', or 'non-civilization', or 'boring and meaningless way of life', or 'non-productivity', or 'failure', or 'inferior', or 'weakness', 'or 'negativity', or 'wrong', or 'madness', and so on. That's their freedom of thinking and understanding, and way of living.
The difference between the awakened/liberated minds and the worldly passionate egoistic restless minds, is merely whether the mind is under or free from the conditional influence of worldly passionate egoistic (family, community, cultural, social, spiritual, religious, political, national, commercial, sentimental...) ideas, thinking, beliefs, values, desires, aspirations, visions, practices, behaviors, actions and reactions, where the awakened/liberated minds don't generate ignorant damaging behavior/action/reaction in this world of diversities that doesn't belong to anyone, devoid of selfishness, possessiveness, discrimination, separateness, or desires, aspirations and visions to conquer and control the world to be or not to be in certain way, and respecting the nature's law of cause and effect, free from attachment and the suffering deriving from attachment, while the worldly passionate egoistic restless minds keep generating ignorant hurtful behavior/action/reaction in the world unto themselves and others, out of selfishness, possessiveness, discrimination, separateness, and greedy desires, aspirations and visions to conquer and control the world to be and not to be in certain way, to be gratifying boundless personal and group desires and ambitions, while drowning in restlessness, greed, discontentment, dissatisfaction, disappointment, frustration, irritation, anger, hatred, jealousy, unhappiness, sorrow, hurt, fear, and worry upon ungratified desires and coming in contact with undesirable selfless impermanent changes and disagreeable experiences.
It's not about which way of living is better or more righteous than the other, but it's about which way of living creates minimum or maximum unnecessary damages to the over-all well-being of all and everything in this world that doesn't belong to anyone or anything.
Inquire the truth of everything.