They killed off the old ones by timebombing the subs with strict requirements for activity. They started complying with takedowns, which nuked wide swaths of NSFW reddit. The death of gfycat was another sudden and massive removal of content.

The NSFW part of reddit didn’t go away though. It’s transformed into OnlyFan spam. So it’s not really porn. It’s redlight district ads. Hot local girls want to meet you!