You've shown that it's possible for human moderation to be awful, you haven't shown that it's impossible for human moderation to work well. It is possible. HackerNews is a fine example.

Paid moderators can have their work supervised (a 'meta-moderation system') akin to Slashdot.

Perhaps, but at least you can talk to a human, which is another aspect of the problem and probably requires a similar solution (more humans).

Reddit also has AI that can shadowban you.