It still blows my mind that the most powerful "personal blocking/filter tool" I've ever encountered was some dude's greasemonkey script that was popular on 4cha

It still blows my mind that the most powerful "personal blocking/filter tool" I've ever encountered was some dude's greasemonkey script that was popular on 4chan in the late 00s. It had text filtering, obviously, which could be applied to name/tripcode/subject/filename fields as well as the body text, but would also take regexes. This is much more useful in practice, assuming you can write a regex. You could give it a list of image hashes to automatically filter. Once smartasses started perturbing images to change the hash, someone made a fork based on perceptual hashing. Recursive filtering (I don't want to see this, nor any conversation it spawned) works better with imageboard-style DAGs of posts because the mechanism is trivial, but is a powerful concept if it could be implemented more generally. I'm probably forgetting a lot more examples but the point is that the ideas are out there and that powerful tools of that sort are definitely possible - it's just that, for various reasons, the big social media players today don't see value in building something like that for their users. It doesn't help that modern social media's general antipathy to adversarial interop prevents a lot of the easier third-party implementations of tools like this.