Remove the chat function
Rather than effectively steal from players (no, a small-text, long-winded agreement that they don't technically own anything doesn't mean it isn't stealing) who use the chat in a way that thin-skinned players feel is incorrect while they blatantly refuse to use the mute function, the chat should not exist any more.
Especially with last patch's addition of the enemy ult ping, there is no longer anything in the game that requires chat to communicate. For the same reasons the public chat was removed, to avoid "toxicity" and spamming, the in-game chat is no longer necessary.
The lobby chat can stay, to communicate picks. But there's no reason to give players the opportunity to hurt someone's feelings if hurt feelings is all it takes to steal from them.