Turns out that even with the limited self-curation power X gives you it's not too hard to customize an experience you'll mostly enjoy; some people enjoy being miserable though. A large fraction of my "For you" feed is just neat artwork/fan artwork, which is peaceful. HN gets in "moods" with what gets to the top and I end up ignoring it for a while. Maybe one of these days I'll try one of the wrappers around HN that try to let you self-curate more. But despite that, for topics I do feel like engaging with, HN still wins by many miles. The "censorship" here is also very light-handed, whether from the staff or from fellow users; downvotes signal to authors that maybe their point of view is unwelcome and they'll be less inclined to post similarly, but they aren't outright removed even if downvoted/flagged to death. I've always had showdead on. I can also easily find stuff that's many years old, and read discussions from many years back that aren't full of "[deleted]" or other nonsense. (I got in the habit with old twitter to automate saving copies of images I've "liked", just like I save copies of videos on youtube I put in a "likes" playlist, because I hate it when things disappear out from under me.)
I have been disappointed that "Not interested" seems to have very little influence over anything on X, it does add some friction on shaping the experience to be what you make it. I pretty much never used the block (or mute) function pre-X, and now I've used it so much. Not just for the never-ending bots or blue-check click farmers either, sometimes it's just "that was such a stupid comment about Y; I'd prefer to deprioritize showing things related to Y, but at least by blocking I can ensure I won't see further remarks about Y from this person, or further dumb remarks from this person about some future Z". I have a little Tampermonkey script for HN that gives me similar functionality, "blocking" (more precisely muting) by username those I've decided I'd just rather not see comments from again for a variety of reasons. I never needed/wanted it before [insert date] but the HN decline has been real. (It just replaces the comment content with an "[unblock]" clickable, so it's cheap for me to give them an nth-chance to see some particular comment, and re-block if as usual it was also undesirable.) Staying out of certain HN threads entirely is the best self-curation one can do anyway, there are topics that just don't get reasonably discussed here yet keep being brought up.