Yes, but what we’re really trying to see is what happens if essentially everyone is a moderator? Or more specifically, what if the only people who can take part

Yes, but what we’re really trying to see is what happens if essentially everyone is a moderator? Or more specifically, what if the only people who can take part in the discussion are those who can care enough about high quality discussion to ensure that they and others adhere to some set of principles that encourage that kind of discussion. Those are obviously the kind of people who should be moderators, but if the whole community of contributors is that kind of person, maybe you could maintain the quality of the discussion as you scale? Of course, you’d grow much slower, and maybe it’s impossible to get that kind of site to a critical mass of contributors. But it seems worth trying :)