I can't remember the exact details, but I believe the attackers also targeted instances? So it's not just that it happens with certain problematic instances, but everyone could have that uploaded to their media storage. And it can come from arbitrary places. I believe that adds to the problem. And it kind of requires to shut these things down for everyone. Or at least everyone except a few excellent hand-picked instances who cooperate, and the moderation tools actually work.

Yes, they've done an excellent job. I just wish they wouldn't have to deal with these things.