Consider the type of person who would willingly become a forum moderator.
A system of volunteer moderators results in the people who most want to be moderators becoming moderators. The people who most want to become moderators are psychopaths. You can see this process in action in literally every forum to ever exist.
Sites live off of volunteer mods, unless they are small like the blf where it's usually the owner who does all the management. It's not scalable however to have a one or two person system, so moderators have to come in to manage the burdeons equally. Not only that, but people usually don't become moderators unless they
willingly do so.
Like... really, how else do you staff a community and manage it. And places do it with pretty small margins of error. While facepunch isn't the
best example, is quite strict and has an over-abundance of mods proportional to activity, they definitely keep out the big time stuffposters and problem users. And in the rare instance of a mod getting out of hand, it's dealt with pretty quickly. I can only think of one mod recently that abused their powers, and that was Big Dumb Patriot and he was demodded and banned for changing someones name.
I think you are mistakening volunteer mods with sociopathic beggars.