Moderation isn’t necessary if you’re willing to just throw the whole site away when it turns to shit.
Well, yeah. Storing your potatoes in the dark is also not “necessary” if you’re willing to just throw them away when they sprout. But wanting to preserve things we like is a given to most people.
I think that’s true if you only have a handful of options, but if you have hundreds to choose from, it’s easy to pick up and move elsewhere. That’s the nice thing about small communities, it’s easy to join multiple and then leave if a couple turn bad. But if you only have one or two, you’re going to fight to fix it.
I prefer the small community form of moderation, the community ostracizes those that behave poorly, and if that doesn’t work, the community moves elsewhere. That’s how social relationships tend to work, and that’s generally how the early internet worked. Now that everything is so centralized, things get more complicated.