I believe this is somewhat a tilt post in the sense that you made this post while tilted by toxicity recently because, well, anyone would be able to see how this is rather unrealistic.
Toxicity is far too broad, thus, Riot's options are fairly limited. Toxicity is a social construct which is impossible to control. Besides, due to the amount of players, even the most regulated communities in any game will include one or two people who spoil the fun for everyone else.
Something like toxicity exists, has existed and will always exist. It's just not something you can rely on the devs to fix, especially something like human nature. The government/police can only do so much about criminals.
So all in all, you can ask for Riot to improve their systems and I believe they're doing what they can, but ultimately, not to discredit Riot, but by accepting the fact that toxicity is a social construct which cannot be regulated, it's best for you not to rely on Riot about matters like this.
Instead, what you can do is rely on yourself, recognize that toxicity is not personal in any way, and through realization and acceptance of other people's personal toxicity, overcome the effects of negativity.
I don't want to sound overly preachy, but honestly, if you make yourself impervious to toxicity, you'll not only be immune to toxicity in game but also outside of it, since human nature transcends League of Legends.
All in all, you can't rely on Riot, but you can always rely on yourself, as long as you allow yourself to be stronger than others. But I understand it's not easy, I have difficulty with this myself. But in the bigger picture and in the long run, it'll be much more rewarding. You're dealing with the issue yourself rather than pushing it aside.
Hope that helps!