It is impossible to eliminate the ego, because ego is false self within the false experience.

Without Self-Knowledge or Brahma Gnana or Atma Gnana there the ignorance will not vanish. Without getting rid of the ignorance wisdom will not dawn. All other paths do not lead finally to Gnana because they are egocentric.  The path of truth or path of wisdom is the only means to liberation form experiencing the illusion as reality.  Only through Self-knowledge or Brahma Gnana or Atma Gnana the waking entity realizes through knowledge its identity with the universal soul or consciousness, the innermost self. –FORMLESS PATH

When one starts inquiry he does it to please himself, not for truth; hence he asks "Who am I?" It is an elementary stage of discipline because it is  based on ego (physical self or waking entity), but aiming at eliminate the ego.  It is impossible to eliminate the ego, because ego is false self within the false experience. Therefore, one has to get rid of the whole false experience  by getting rid of the ignorance.  There is need to understand “What is mind” in order to assimilate the true self-knowledge.

The formula "What is I?" presupposes the existence of an ‘I’. But this is only an assumption. Before proceeding to act on such a formula one ought first to inquire whether there is such a thing as an ‘I’.

Those who have been baffled by unsuccessful inquiry, reading, intellection, have to find out what are the obstacles on the way what is blocking them from grasping ,understanding and assimilating the non-dual truth.

Yoga is intended to remove the hindrance in pursuit of truth such as sexual desire, worries, anxieties, desire for wealth etc. Also to enable the one  to keep out irrelevant thoughts whilst making inquiry, analysis and reasoning .

All this has to be done before indulging in pursuit of truth. Therefore yoga has only a negative value and is a preparatory stage. Pursuit of truth starts from what is seen, i.e. the three states.  Wisdom comes from both knowing the three states and the formless witness of the three states.

To leave out one of these parts is to prevent attainment of wisdom. "Who am I” is useful no doubt, it has certainly a value in its place, and gives some knowledge of self as, the Witness. But what about the witnessed? The three states are mere object to the witness. It must also be looked at. If the witnessed [three states] is ignored, then "Who am I” cannot give the full truth.

“Who am ‘I’” is   yogic enquiry; not the spiritualistic; the latter deals with the whole of life whereas the former deals with a part only.

"Who am I” inquiry limits only to the physical entity, because there, is no person in truth but only in the illusion of mystics.  ‘It should be "What is  I?"

The question "Who am I” is a religious, not a spiritualistic question. It is a most selfish one. It is on a par with "What shall I be after death?" and "What shall I get in return for my good karma in next life?" It is purely egocentric and it is based on the false self.

Only the people who are serious in knowing the truth can lift their thoughts above ego and ask "What is the mind?"  All  the three states  put together make the soul/self, not merely the ego questioning itself ''What is  I.”

When one is absorbed in thinking of anything, he forgets the subject, which consciousness the innermost self, that which witnesses all the coming and going of the three states in succession.

 One may think for hundred hours continuously but it is all thoughts, hence not consciousness. But when one becomes aware the thinker of the thoughts are one is essence, one do get consciousness, the knower, the formless witness of the three states. Consciousness the innermost self is the eternal.

One has to get rid of his doubts, But that did not mean, simply go and believe everything he is told. The doubt is to be got rid of "by the sword of wisdom. 

WHO AM ‘I’ and ‘I AM THAT’ is only for a lower stage where one gives up externally in order expose the false nature of the ego, which is not full truth. To get ultimate truth one has to inquire into the nature of the mind, which is in the form of universe.  Inquiring into the nature the mind or universe is higher.  Thus ‘WHO AM ‘I’? and ‘I AM THAT’   will not reveal  the truth of the whole(form,time and space) thus the journey is incomplete.  

 ‘WHO AM ‘I’ and ‘I AM THAT’ serves only at starting point. What one has learnt from the teaching of the sages be understood through exercise of reason as far as the reason might go.  And what one has assimilated must be realized. There are stages in the seekers goal. 

Self-awareness does not mean one is transforming something into something else. In self –awareness there is no second thing exist other than consciousness in the midst of diversity.  The body and the world have become on in essence. There is no duality in the midst of duality.   There is not even the concept of real and unreal. Of course it does not mean that when one is involved in practical life within the practical world disappears. But in self-awareness one is consciously aware of ‘what truth’ is and ‘what is not truth’ in the midst of duality, because one sees his ego, his body and his experience the world as consciousness.  Thus for a Gnani there is no second thing exists other than consciousness even though he is in the midst of diversity.