It might be nice if lemmy clients (voyager, default client, etc) would make a suggestive pop-up:
Would you like to block this community? Your downvote ratio is 100% over the last X days/Y posts.
This is good for lemmy because it will let users have a more positive experience, its helping guide people to get better use of the user interface.
If would be more productive to encourage blocking by making it more powerful/less of a chore.
Also honestly once a block list is 50+ it already seems like named blocklists are needed to properly manage things.