Mute Allied Chat is the GREATEST thing ever
I LOVE this feature!! I have been a heavy user of /muteall but often you forget or decide to give the benefit of the doubt every few games, only to regret doing so. Not only can I not hear anyone, but no one has to hear me either! Not that I'm not toxic or rude, but I have called out bad plays in ways like, "Meh, why'd you do that... Garen is 10/0 you can't just keep running at him trying to solo", which can tilt people even further.
I have just been communicating through emotes, chat notices, and pings. Don't need anything else to focus on winning the game.