I think the things you describe actually have more to do with decentralization and small communities then the concept of forums in general. You can see similar

I think the things you describe actually have more to do with decentralization and small communities then the concept of forums in general. You can see similar weird rules and requirement on mastodon instances these days. And while they can be a deal breaker, often the same quirkiness makes communities interesting in the first place. I don't think the behavior of toxic communities is solely based on the kind of software they use.