Facebook and Reddit are successful BECAUSE they are censorship machines. Facebook spends far more man hours on "curating" content compared to engineering.
Same with Reddit. Add up all the "moderation" time spent removing negative or controversial posts and I bet much more time is spent on content compared to programming the site.
You are not wrong, but even if a perfect decentralized clone existed tomorrow you'd only get young men and programmers to use it, the average TicTok users wants to see beautiful people doing stupid things, they don't care how it happens.