Why banning people leads to more toxicity

Suppose someone is toxic. They get banned. They create a new account, and then are not only toxic, but smurfing- which leads to other people (on the other team normally) getting angry, and yelling at one another, etc. thereby resulting in more bans, suspensions, etc. It makes no sense to ban toxic people because it just creates more toxicity in the long run. Or- if u still feel bans are appropriate do something to limit the number of accounts someone can make. I constantly see toxic high level smurfs in low elos flaming their opponents (or their team), and then more bans resulting. Bad games happen, bad days happen- but there are too many reasons to get in trouble, and too long of a punishment when it happens. As a result the toxicity spreads. And how often does someone do poorly and then their team flames THEM, they respond and get 4x reported by their team and get in trouble. It makes little sense to ban for inting, and also for afk- it seems there is no way to avoid punishment if ur playing against someone of much greater skill. Different playstyles are not reflected in the champion pool, but in the game- a passive adc and an aggressive support could both play with each other and end up having completely opposite ideas of what the "correct play" is. If the jungle pings help at dragon, no one comes, then enemy jungler shows up and kills him, hes behind all game, etc, etc theres lots of ways to lose and only one real way to win- teamwork- and its very rare that 5 random people will actually be a cohesive unit. As such, smurfs run the show, and as previously stated lead to more toxicity. Its a cycle which needs adjusting. Ty for the consideration