For me I think it was doomed from the start because of its voting system that conditions users to toe the line or risk being down voted. Socrates hated democracy because it let dumb people vote and on Reddit the exact same mob rule issue exists. the user base quantifies your posts and comments not by how true they are but by how well they fit the narrative of a subreddit and spread its and ideas. For example a comment saying "FUCK TERFS!!! TRANS RIGHTS!!" would likely get many more up votes than a well thought out comment or critique of LGBTQ issues on a trans subreddit. this is almost exactly the kind of future described in the game MGS2 where "no one can be invalidated but no one is right". I think 4chan does things way better by having most boards be on broad subjects instead of specific ones.
I think the vote system is a big part of it. You got stickers here but no one really cares. Yeh you might subconsciously skip over posts that have 20 autismo rates but no one is hiding your comments and shadow banning you because you disagree with the prevailing opinion and are getting downvoted into oblivion. They basically created a systems turbo boosting herd mentality and circlejerking for asspats. Any dissenting opinion gets swiftly stomped down.
Its not even a case of 'dumb' people specifically like the Socrates example. You can disagree with the prevailing opinion and get a tsunami of downvotes even if you express just that, an opinion.