The free mods are why the site sucks. It incentivizes power-trippers to gatekeep large communities without any common consensus on how moderation should be established, and without any oversight of the moderators.
There's no standard of professionalism or repercussion for being a terrible moderator, most of them are anon socially-weird outcasts with a chip on their shoulder.
When you're paying someone real money to be a moderator they tend to do a good job because they want to continue receiving that payment. The reward for a Reddit moderator is instead to feel like you're important and powerful, and that you can punish people you disagree with.
It also means that their power can generally be easily bought, because again, there's no repercussions for manipulating the board. Reddits incentives are entirely broken.