Before you make a post about balance, please realize one thing

A game like League is always in development. Whenever Riot thinks they got a champion into a perfectly balanced state, a bug shows up or people try a new build that makes them super strong again. With Yasuo being a good recent example, Riot unintentionally buffed him pretty heavily by fixing a few bugs that made him less reliable, while simultaneously a new tank-heavy build with Trinity Force and Frozen Mallet popped up. This new build made him very hard to kill and made it very easy for him to kill you. He still hasn't bounced back to the point of balance that he was before these bug fixes, and Riot doesn't seem to be targeting him with the nerf bat any time soon. So, if you don't like him, ban him. Next season, we're getting 1 ban per person (10 total bans), which means that Riot can probably be a little more free to do experimental changes on champions when important pro games aren't being played; if the champ is broken, there's almost a guarantee that it won't get through a 10 ban ban phase. Yes, the blind pick players will always be complaining about them, but that's just how it goes.

TLDR: the game is always a work in progress, and will never be perfect balance-wise. If you don't like a champion, ban them.