I feel pretty confident saying that we should basically never fold sets in 3bps on the flop. Even if villain has a straight or a flush already, we still have good equity. Villain can also stack off strong hands like 2pair, top pair top kicker, overpair, combo draw, or pair + draw type hands. We also have pot odds. The only true disaster scenario is if we're getting oversetted, but like...it's 100bb deep 3bp, sometimes we are just meant to lose our stack.
I hope nobody comes in here (after 100bb effective clarification) and says "it depends," because this is one of those spots where it reaaaaally doesn't
Contextual factors and adjustments are an important skill in poker. But it's also important to recognize spots where we have mandatory stack-offs with very strong hands, to not mindgame ourselves in those spots, and to accept the fact that sometimes we are going to get stacked in those situations and that's ok