Sage Sri Sankara says: - Yoga is not the means of liberation

Yoga helps the yogi by giving him the feeling that the world is not worth bothering about, it detaches him from the world; it makes him treat the world as a dream, i.e. an idea. It does the same to his ego to some extent because he becomes indifferent to what happens to him. But this is only feeling, he feels these things only but does not know that the world is mere mirage. Such knowledge can come only after the soul-centric inquiry and reasoning and in no other way. That is why yogi cannot be Gnani. It is the difference between egocentric and soulcentric knowledge.

Yogic experience is based on individuality. Individual Feeling or opinion   that the world is unreal may change in the future because all individual emotions are liable to change; and the fact is that individuals do change, as when they indulge in circumstances of practical life within the practical world   and they lose their sense of world unreality though previously they felt it. A permanent view of the world as unreal or illusion can come only after soulcentric inquiry and reasoning; such knowledge cannot change.

Where one is sharp enough to grasp   he could discover the  fallacy of the three states  by soulcentric  reasoning alone and then it would not be necessary for him to have gone through yoga practice at all; that is why  yoga is for dull or middling intellects.

To know the whole truth, you must know all the three states, otherwise one gets half-truth. One has to inquire into the world that   confronts him. If one drops the world confronting him means it is his   incapacity to do a deeper self - search.

Visions and Samadhi are illusions from the standpoint of the formless soul, the innermost self. In Mandukya it is given that Samadhi and sleep are identical. Brihad Upanishad does not advocate Samadhi.  In non-duality, contemplation has no meaning.

Sage Sri Sankara says: - Yoga is not the means of liberation (page 132-133 - Commentary on Brihadaranyakopanishad.

One cannot get rid of ignorance through Yoga because yoga is practiced on the false self within the false experience.  Without getting rid of the ignorance false self and false experience will prevail as reality.

Those who are practicing yoga for long years and found tit it to be inadequate and useless to realize ultimate truth or Brahman   should leave must take path of wisdom in order to acquire Self-Knowledge or Brahma Gnana or Atma Gnana.