If there's one thing I've learned about human beings....
Is that they are stupid and lazy. If you ban toxicity for 3-day suspension every time they offend you may deter them far more than warnings. It's a soft punishment but done often enough the person will just be sick of the inconvenience and learn to stfu. 2 offenses in one week, you only get to play twice that week. Too bad.
I don't think permanent banning works. But there needs to be a responsive system in place.
The trolling in this game is completely out of control. For me, It's 1 for 1 every game. Every win will be another loss after that I have to magically overcome. Which I have by playing hypercarries but is that really what people need to do at low elos? I'm literally crawling at 2 LP every two games to the next division.
Is that good game design? Is that right in your mind, Riot?