Heh, I came to a similar thought walking home after asking the question... that it seems at least plausible the only kinda powerful optimization processes that are simple enough to pop up randomlyish are the ones that do random sampling via variability.

I'm not sure it makes sense that variability at the population level is much explained by coming from evolution, though. Seems to me, as a bound, we just don't have enough points in the search space to be worth it even with 6b minds, and especially not down at the population levels during most of evolution. Then there's the whole difficulty with group selection, of course. My intuition says no... yours says yes though?