I used to daydream of a 'dark web' but for humans not criminals. But at this point I don't know how you'd keep slop out, given how high human collusion has gotten of late.
Small private discord or slack servers meet this definition. I'm part of a few interest related ones and I'm glad to know members are more likely to be human than not
Why wouldn't it? I am in a few cozy small discord servers, and I don't see why anyone would pollute it with AI comments. And even if they did, the mods would simply ban them