From Advaitic perspective, the yoga is useless for realizing the truth, which is hidden by the form, time, and space.+

From the Advaitic perspective, yoga is useless for realizing the truth, which is hidden by form, time, and space.

The yogi shuts his eyes against the world and then has the temerity to declare that he knows the world to be Brahman! Because he has not inquired into the world in which he exists, he knows nothing.  Yoga cannot remove ignorance. It is only a step. It removes obstructions.

Bhagavan Buddha gave up yoga after practicing it for six years. He saw it could not yield truth. 

Bhagavan Buddha gave up his austerities of yoga as impossible and useless. Thus, Buddha got enlightenment only after he gave up Yoga. (Page.70/71 "Buddhism in Translation” by Warren)  

Sage Sankara definitely says: ~ Yoga is not the means of liberation (pages 132-133 of his commentary on Brihadaranyakopanishad).

In Sutra Bashya and Manduka: ~ Samadhi and sleep are identical.

Brihad Upanishad does not advocate Samadhi.

Self-knowledge or Brahma Gnana or Atma Gnana cannot come if anything is left out. The whole universe must be included. For only when all is known can all be known to be but ideation. Hence, the yogis blotting all out in Samadhi cannot lead to Gnana.

The yogi holds the Self as ‘I’ his practice is based on the ‘I’ without knowing what ‘I’ is in actuality.  The yogi may get the knowledge that the Seer is separate from Seen, but he will never know Brahman without inquiring into the world, because he is giving up the world, and hence cannot discover his unity with the world.

 The Gnani regards everything in the world as Brahman; the yogi rejects the world. Thus, there is a fundamental difference.

The seeker of truth should not believe all the stories about the magical power of mantrams, visions, samadhis, and astral travel because they are a reality within the dualistic illusion.   Wherever there is duality there is no truth. 

Remember:~

When you know that everything is Brahman, there is no need for the yogic control of the mind. Control presupposes a second, a duality.

Hence, yoga is in the sphere of duality and is unnecessary to one who knows non-duality.

If anyone talks of liberation he is forming an idea.  The idea belongs to duality. Those philosophers, who are so confused as to be unable to separate the subject from the object, talk of gaining liberation. But all such ideas are only the dualist illusion (object) which comes and goes, the Subject needs no liberation because the object is created out of the subject. Knowledge of the subject frees the subject from the illusory object.

The Soul, which is present in the form of consciousness, is the ultimate truth.  The ultimate truth is Brahman or God.

The final state is that God is everything, the All; there is nothing but God, whereas to say "God is in me" is mysticism.

The world in which you exist is consciousness. Unless the world in which you exist is there in your realization, the Advaitic wisdom will not dawn.

Ignorance cannot go through merely knowing the Soul, for it is known in sleep and Samadhi. It can go only by the realization of the Soul, which is present in the form of the consciousness, is the ultimate truth or Brahman because there is no second thing exists other than the consciousness.:~Santthosh Kumaar