I mean, they should probably feel like fools believing there was child sex trafficking going on in the basement of a building that has no basement, even if some other conspiracies turn out to be real. It's a textbook case of mob mentality that so many people believed the lies and nobody did even basic legwork.
(And let's note: it's not like 4chan broke open Epstein's crimes. Old fashioned FBI legwork did. And the guy had a history of sex trafficking already, which nobody in Pizzagate did. As fun as it is to pretend to be an armchair sleuth, it sure isn't a pass-time that's got a good batting average over professional investigation).