While PF Discord users can block messages from other Discord users, I'm currently unaware of any similar function existing in in-game chat. Speaking as someone who has several people blocked myself, if a block function for Minecraft chat, protecting against viewing global and direct messages could be either made more visible, or implemented, that'd be grand.
I think there’s a command for that already. I don’t remember what it is though. That being said I do agree that it should be made more visible.