A thought that came to mind regarding toxicity...
Why doesn't Riot tell you that you're being toxic before you're punished for it? Considering they list multiple instances, it's not as if they necessarily can't. It'd be beneficial, for new players at least, for Riot to tell people that they're being toxic when it's reported, with a quote of the toxic dialogue.
From personal experience and many threads here, when people are punished it's usually because they don't know that what they're saying is punishable. It'd benefit both the players and the game environment if instead of waiting until punishment to tell someone that their dialogue is toxic, just tell them when it's reported.