Currently users you block can still see your posts, reply to those posts, and trigger notifications when they do reply.
You can read the beginning of messages people you have blocked in your notifications tab, but have to unblock users to see the rest of what everyone else reading the replies to your post can see.
A “blocking” feature that is only inconvenient to the blocker is worse than no blocking feature at all, equivalent to trying to escape a fistfight by turning invisible but actually just closing your eyes.
Got to tell you “they can’t even see your posts if you block them (when logged in to that account)” would be preferable to me, but even what you describe would be better than what currently goes on here.
Currently as I say in the OP people can reply even if you block them and (the beginning of) those replies trigger notifications (but when you click on them you can’t see the entire post.