Please keep open mind. Bans and free accounts.
The problem: Yasuo is being toxic in my game.
The encouraged solution: Mute and report Yasuo.
Look, closely. That hasn't actually solved my problem. Yasuo is still, and will always be toxic in that game.
A preemptive mute solves verbal toxicity. It does nothing for game play toxicity.
Back to mute and report, Yasuo is banned. Yasuo buys a level 30 account. Yasuo is back in queue within 5 minutes.
To recap, Yasuo is toxic in my game and is still playing. Even after muting, reporting, and banning. The problem has not been solved.
My humble opinion: Improve non-verbal communication. Implement mute feature in champion select and auto mute people on a mute list. Stop banning accounts. Implement a personal surrender system with report functionality. Extreme offenders are black listed but not banned.