My personal view is that the waking state is not like dream state, and they are truly unrelated. Infact, srI shankarAchArya has rejected the dream analogy in the interpretation of the sUtra 'vaidharmyAchcha na svapnAdivat.h'.

From the point of ajAti vAda, there has never been any creation/destruction because paramArta satya is akAla where no events or changes happen. Therefore, creation/destruction exist in the paramArta only in the form of knowledge (like pages of a book) without 'timed' information. It is due to this mysterious mAyA that such 'vyavahAra knowledge' appears to be event driven phenomenon to us, and appears real. It is kAlA that tricks us into beleiving that creation and destruction really happen. If you reach to the stage of trikAla abhAdita satyatva, then the world (as it appears to the ajnAni) disappears and only Atma exists.

The actual creation in vyavahAra dasha is not like a dream, but like ripples that appear in the ocean of sacchidAnanda - ripples of thought that create imaginary upAdhis that creates jIvas who feel bounded by these upAdhis. Though these upAdhis are imaginary, it is no joke to overcome them, and that is why shAstras have described elaborate ways starting from righteous living and devout worship to rigorous meditation to achieve enlightenment. Creation happens by mere wish of God - 'ichchAmAtram prabhosshRshTiriti' - the wish here is akin to God creating many imaginary concepts (like complex numbers) and weaving a big plot with all those imaginations...

I dont personally think dreams and sleep can help with enlightenment. Meidtation is always done in the waking state, and if you happen to fall asleep and enter dream state during meditation, no benefit will come about. It is extremely important to retain the waking state ( this is why shAstras make the sitting posture or padmAsana mandatory for doing meditation as it is difficult to involuntarily sleep while sitting) during meditation. It is from the waking state that one can enter turIya after crossing the svarga loka (taijasa or the subtle world) and brahma loka( prAgnya or the causal world).

When we sleep at night, we do enter the world of taijasa, but since we are not awake - we cannot control the dream and dream happens from previous vAsanas. If we can enter this taijasa world from the waking state through meditation, it becomes a world where dream experiences can be controlled by you - this is what that gives Yogis their great powers and siddhis. If we can enter the pragnya world through meditation by crossing the taijasa world - we get the ashTa mahA siddhis, as everything we wish for is instantly materialized in this causal plane. There is also vision of sarveshvara here. If we cross the pragnya world ( which will need burning away of significant karma vAsanas) we enter the turIya state that is beyond description. It is a tough ask...and will remain a mere theory for most sAdhakas for many births to come...