To play devil's advocate, as a species we've spent the vast majority of our existence sleeping on the literal ground. It seems plausible there may be some adaptation to the electrical properties of being at the surface vs ensconced in synthetic materials above it.
Granted there's no evidence for that as of yet, but there was a time when fiber in food was reasonably seen as just inefficient waste that couldn't be digested and so had no benefit, that's part of how we got Wonder Bread and the obesity epidemic.
Granted there's no evidence for that as of yet, but there was a time when fiber in food was reasonably seen as just inefficient waste that couldn't be digested and so had no benefit, that's part of how we got Wonder Bread and the obesity epidemic.