I’m pretty sure blocking (if you’re using a Lemmy instance anyway, which looks like you are) doesn’t block users, but only the communities from the instance you’re blocking. I think I’ve heard that Piefed blocks more extensively though, probably including users.
Block the ani.social instance and it takes away 90% of the anime groups.
but I don’t want to block their users
I’m pretty sure blocking (if you’re using a Lemmy instance anyway, which looks like you are) doesn’t block users, but only the communities from the instance you’re blocking. I think I’ve heard that Piefed blocks more extensively though, probably including users.