Valid points ..but let's parse this statement a bit more

so the big guys make the most

In my understanding not everyone makes the same % ROI ( big guy vs small) so the smaller staker gets very low % ROI hence there is an element of market risk , albeit it's more of a winner takes all.

What is proposed here is everyone gets the same % ROI as cold return.

If every staker gets the same % ROI , I concur with your point and find both situations to be quite similar.

Bid bots still operate with a market risk that tomorrow any of the UI may decide to ignore the posts upvoted by them so they have an incentive to keep adapting with the ecosystem.