There will never be balance.

With champs like zed, yasuo, rengar, and talon being very strong right now people like to cry for them to be nerfed. One thing, if you nerf them then another champ will be indirectly buffed and take their spot on the totem pole. For example, if you nerf zed, he falls out of place and doesn't match up well with other top picks someone who can will take his place. This happens every patch and its always the same result. Someone is buffed, becomes a god, gets nerfed to shit and then falls completely out of meta and is replaced by someone who is indirectly buffed because of it. There are about 120-13 champs in league and with that significant number there can never be a state where every champ is viable and no one is able to faceroll a game.