Riot, you need to spend some serious effort/money cleaning up the community.
It's bad. Really bad. I know they like to say it is improving and that they are doing stuff, but it's not enough, and since I started playing years ago it's only gotten worse. People don't fear any repercussions on here. They do and say whatever they feel like, and laugh off the idea of getting reported. They have been trained by a community that basically has been allowed to be this way by Riot. If you start 2 week banning every single troll, I guarantee you this place would start to improve, but you won't even do that. Why?
What you have been doing for the last 3 years hasn't even been enough to counteract how much toxicity spreads itself naturally when it's unpunished. If you don't change something seriously impactful about how you police things, it's not going to start improving. It's gotten so common that you can't even really play ranked and expect to get a real game. If people lose nearly every game with a troll on the team, and win nearly every game without one, all the rank seems to indicate is teammate luck. Is that what you really want?