You want to have 3 15-seconds long uninterruptable ads when you click on a post? I don't think one can compare the content quality of a youtube video with a single post and they'll never generate the revenue that youtube does. You already can get moons on reddit in one or some subs, but that only led to a lot of bullshit posts, so i don't think that is the right incentive and you wouldn't like the outcome. They should pay moderators though, but since there are so many that enjoy doing it for free, that probably won't happen either, only maybe if they dig themselves deeper into the current mess where every moderator flees the site.