@js I think there's a middle ground to be found there: I suspect most users don't want to curate their moderation, especially not for egregious cases. Block lists also have the benefit of being preventive and not reactive, which is important when talking about potential harm to a user.
I also think people feeling unsafe being themselves (please don't bring up the paradox of tolerance) is also more likely to break the Fediverse than defederation. The latter is theoretical, the former happens now