Is it Even Possible to Balance this Game?
The boards are constantly complaining about something. Either something being too strong, or something being too weak. There's over 100 champions in the game with wacky interactions and different kits. I don't think this game can ever be 100% "balanced". Sure there can be metas that are more fun that others, but since I've played this game, there's always been something "busted".
But I have stuck around to notice something. What is busted one patch will be weak in another patch. Riot has even stated this before. They choose certain classes or champions to be strong at different points in the meta. So ADC will be too strong in one part of a season, while they'll be weak in another. And they just shift around what is strong or isn't strong. The players who don't play those champions will complain and those who do play those champions will be happy for some time.
That's all Riot can really do. Is make champions feel fun to play (aka busting them or making their counters weaker) in different intervals. Cuz not everyone plays immobile mages, not everyone plays assassins, or tanks, or bruisers. Riot likes to say it's to keep their game fresh. Whether you like the practice or not, oh well, it's their game. Sure some of it is influenced by LCS picks because of money, but it seems like every champions gets to be in the spotlight at some point.
They deliberately keep the game unbalanced essentially. Because I'm going to be honest, I don't really know what a fully balanced League would even look like. And neither do you, because you have a champion bias. And neither does Riot, because they only care about who's playing what champion. They don't want their game to always feel bad for players and they don't want the meta to become stale to the point where you need Smash bros melee professional game sense and tech to have a chance at winning games.