Anyone who has run a forum knows that mods are paid, usually with ego or duty or power, but they certainly get something from it. Else hundreds of people wouldn't want to be moderators of small phpbb forums much less thousands of people on reddit.

Either way, I don't think compensation swivels the "entitled, power-tripping reddit mod" trope where they ban from their subreddit if you make a comment they disagree with. It's one of reddit's biggest problems.