The Toxic people in league

Why is it in almost every game i play people afk, tell others to die and other many horrible things and do not get a single ban, and in a game where you need teamwork to win... people do not care and feed if they don't go 20/1... the toxicity of the leagues community is remarkably high. I Have been a avid player for years now and attempt to play and get to higher ranks but this is almost impossible to achieve due to people claiming to be smurfs and feeding in my ranked matches. Without a single consequence, many if not all league players are tired of this.. I am tired playing a game and i have to mute everyone or keep my mouth shut when people feed and i get reported for " not ff'ing" .... why has this never been fixed..