Reddit like all social media sites works like an ecosystem: a few people provide most of the content and discussion, with others reacting to that and driving interaction. Unfortunately, Reddit has embarked on a systematic policy of (1) allowing a shadow cabal to censor un-narrative content and (2) acting against ideas which offend its SJW fanbase.
Many warned Reddit that by applying this policy, instead of reasonable free speech -- which might permit dangerous facts and arguments, but not slurs and personal attacks -- it would drive away the core of its userbase. Reddit shrugged and figured that it would still have the giant neckbeard echo chamber.
The problem, as has become visible, is that content is declining. The reposts which are too consistent to be anything but managed by site staff remain, but new content is paltry, especially in the formerly big subs like /r/pics, /r/funny and /r/aww. There is no way to get hard data on this, but comparing memories of old and the amount of images and links saved from that time to the present shows a radical fall.
Reddit wanted a userbase it could control so it could market itself to the nexus between SJWs, hipsters and incel basement dropouts. In the process of seizing control and making a "safe space," it drove away the unsafe but creative forces that were responsible for its rise. In the end, what will doom it is not censorship itself, but its secondary effects.