You are wrong mate. Honestly. Dead wrong.
The most toxic thing anyone in this game has to deal with is players trolling/inting and the like.
Chat flame can be too much at times but its just words and can be muted.
It's a total joke that you can play game after game encountering players intentionally who deliberately troll you/dont try to win in ranked etc. And they won't be punished.
But as soon as you use a few flag words of offense you will be punished and punished quickly especially if there are a few instances.
It's a complicated issue. But for me there is no comparison between someone insulting me(which i can simply mute) and someone deliberately wasting my time.