It sounds more like they want to compete with either Patreon, OnlyFans or both. Though reddit as it is now is a horrible place to build a community. It's hard to keep bad actors out, but moderation (and the culture surrounding most moderation on reddit) is also completely opaque. So you simultaneously have a problem repelling trolls (participating in trans subreddits essentially guarantees hateful DMs), but you can also shape comments in their entirety to make a place a perfect echo chamber. Entrance fees might actually solve this problem.