The purpose of a blocklist is to have a large group work on the large task of identifying a certain set of trolls, and then share that list automatically with themselves.

Individually blocking 8 or 9 trolls yourself as you browse 20 new indie games becomes a laborious task. But, if a community of hundreds all knows “Yeah, every time someone posts the ‘Please include LGBT!’ comment on these block-matching puzzle games, it’s a troll” then 99 people don’t even have to wait until they’ve identified trolling and blocked it each time.

Bluesky uses these sorts of blocklists, and it works pretty well. By having members opt into them, it evades the issue of Valve “promoting an army of hundreds of highly opinionated moderators”.