I see what you mean. Yes, I agree, it’s in some sense suboptimal for a community to outsource moderation to a larger entity.

However I think moderation is difficult (and this fact is under-appreciated) and so the limit of “perfect moderation per community” is probably not practical. (Indeed I’m not even sure that’s a possible thing, since each community member might disagree, even though there are emergent norms at any given time within a community.)

Absolutely, and those norms are best enforced by that community.

I feel like I'm describing a social network I should be building. Or has already been built.