Without Section 230, self-hosters have to choose between screaming into the void or playing Russian roulette. You'd either have just your own content that you'd have to self police, or have a comment section where anybody could post something "objectional" that you would be responsible for. Online conversations would effectively be over, right down to email providers once a chain letter gets going that says something the authorities don't like. Section 230 might enable some bad things, but then again, so does free speech. The cost is worth it.

Yeah, social media would also have to decentralize.