I was head mod of a national sub for 2 years so I’ll offer their perspective.
Big subreddits are constantly attacked by clever ways to self promote. Your trust was broken so many times you were forced into cynicism. Your rules need to be simple and treat everyone equally. You don’t want to make too many judgment calls because they’re always controversial. You don’t want to spend that much time moderating because you’re not getting paid. You don’t have a way to increase your headcount because people who can mod are a precious resource. You have to maintain cohesion within moderation team because you’ll end up squabbling rather than gardening.
But there are also mods that are just scared of losing power.
Yoghurt that they make out of this poor Balkan man is very tasty when combined with garlic.