OK so yes, you have a language filter and a mute options within the game, but alot of people do not use these options and keep them off. Why, because of their peers probably or just the urge to read and say something back to another player with toxicity in mind. The ability to block out words is out there so why does Riot allow those words? Obviously Riot doesn't take a stand to online bullying, racism, or any other form of hate speech even though they have their code of conduct they still allow the action of words to pass instead of preventing it. Mind you League of Legends is rated T for Teen which is 13+, so Riot is going to allow that to be passed on to kids who honestly are unstable emotionally maybe even mentally in their time growing up.