On the standpoint of the formless Soul or consciousness, the three states are non-existent as reality

Deeper self-search reveals:-

The witness is the formless Soul, which is ever present in the form of consciousness. Without the Soul or consciousness, the three states cease to exist. Therefore, Soul or consciousness itself is the formless substance and witness of the three states.

On the standpoint of the formless Soul or consciousness, the three states are non-existent as reality. In waking or dream the self becomes ignorant of its own formless,  non-dual nature and it experiences the duality as reality.

When ‘Self’ is not the physical  than analyzing the three states on the base of physical self or ego creates the ignorance.  Ignorance   leads the seeker towards imagination or intellectuality. Intellectuality is mere speculation derived on the base of physical self or ego(waking entity) , which is the false self within the false experience (waking)