There are a bunch of dead subreddits, forums, sites, etc due to over moderation. Facebook is kind of a dead platform itself, being carried along by other properties, in part because of moderation mismanagement (also in part due to a changing demo.) And their moderation has actually been better than Twitter's in terms of transparency. There is certainly a delicate balance, there's no denying that, but there has to be some level of transparency and accountability for the censors or it just doesn't work. You can't have the whims of a moderator determine the fate of accounts with no explanation or consistency. Twitter has been an utter failure in this regard, even Jack had no explanation for some content bans and inconsistencies. The current CEO is even more aloof, or just supports the lack of transparency outright.
A more fair moderation system doesn't mean Twitter is going to turn into 4Chan. Everyone seems to hint that is going to happen, but have 0 evidence to support their claim. It just seems like some people are afraid some speech they disagree with might once again be allowed, like during early Twitter...it's almost like a power thing.