Why aren't people muted in post game client when you block them in game or in general

Seriously, you mute people so you don't have to see them constantly shittalking you, but you get to the client and oh look, they are still talking to you. Blocking someone: Removes them from your friend list Blocks friend requests from them Blocks game invites from them Blocks any future conversations

Yeah the last one surely works. You can't even mute them in client. Why not?