Platforms like HN are still vulnerable to astroturfing and bubble effects, but at least the operators aren't optimizing for engagement beyond [what I assume is] a fairly simple up/down ranking system based on user votes and time decay.

Moderation is another question. On HN again I don't really get the sense that there is a lot of censorship. On Reddit, on the other hand, the behavior of moderators and admins is legitimately frightening once you start paying attention.

Overall I would shut it all down forever if I could, but if I had a limited budget I would prioritize Meta's platforms and similar algorithmic infinite-scroll slop feeds. I think all they do is addict people to scrolling and epistemically poison them without giving any real value back.