@Edent as you note

Again, it isn't impossible for a blocked user to see content - but technical restrictions means it takes effort. And, it turns out, for all but the most obsessive abusers - a mild bit of UI friction is all that it takes for them to stop.

and (as someone with over 50,000 confirmed kills blocks on Twitter) I feel like you downplay the value of this friction too much. It made a big difference for me.

Regarding Bluesky, I find the public blocklists very useful - I can crawl my friends blocklists and block accounts that enough of them are blocking.

On Twitter, before Space Karen took away our toys (API access) I had IFF (identity friend/foe) scripts that would analyze followers and following data to try to determine how to deal with people.

My mass blocking was based on follow/follower network analysis, and I probably had the most complete blocklist of anti-trans bigots for a while. They sometimes got upset that they were preemptively blocked even though their accounts were fairly new, they'd never interacted with me, and they weren't on any public blocklists.