I think it's a simpler problem: the general public these days uses the internet from phones, not computers with actual keyboards. Phone just discourage longform text and nuance, and encourage 180-character quips. Even if you had a well-moderated forum that kept trolls and bots at bay, the average quality of posts is going to be poor compared to a decade-plus ago. No one yet fully perceived that yet back when Reddit alternatives were first proposed.