But that's also just ignoring the fact that humans seem inherently drawn to the fantastic, whether in religion or something else. There isn't really any reason to believe that wouldn't have existed 40k years ago, correct?

That's what they mean by begging the question; you don't really get much useful information from trying to cite something as evidence of what you've already assumed.

This is the earliest evidence of such fantasy we have. It's not that this piece at this time was the earliest human fantasy, but there is a cutoff line somewhere between humans and our last common ancestor chimpanzees.