Not having evidence nature pre-existed the Big Bang has led to brilliant theories explaining something from nothing? Certainly not from NOTHING. We can’t see far enough for anything existing prior to the Big Bang to prove it. But, this is not evidence of no existence prior.
Perhaps the true answer is the most obvious, but science can’t ‘hang its hat’ on even a logical assumption: don’t remove nature from the theory. Occam’s Razor : ‘don’t add or subtract entities in a theory beyond what’s necessary’. We have no evidence to remove nature. Proven is entirely natural occurrences took us to present day from the instant of the Big Bang.
Occam’s Razor frees the logical use of nature and makes the most sense; that nature pre-existed the Big Bang. That nature is eternal. There is nothing outside of existence, and existence is natural. Therefore a limitless multiverse is logical. The closest universe is too far to see.
What makes the least sense is the assertion of supernatural powers, those falsely claimed post Big Bang again asserted pre-Big Bang, of a god that had no part in scriptural ignorance, claimed existed for an eternity (realize an eternity is mind bending in both directions, past and future), capable of creating something pleasing for itself, yet waits an eternity before creating the Big Bang, nature, and humans to worship it, who only occupy an unimaginably tiny fragment of its entire creation. Considering all things, I am 100% certain no god had any part in anything. God does not exist. Scientists may envy my freedom of conduct to state this absolute.