Not effective counter items
I been playing league a lot and i main tanks (like Rammus) and yet i still sometimes struggle against adc or ap damage champions. I feel like i get erased too much and there is not enough effective counter items. In this game a mistake early can be very costly and it is difficult to catch back up and to get counter items for enemies are just... not too effective when you are behind. Even when i play as kassidan i can erase enemies late game and similary they can erase me. Edit: I'm not gonna say stuff like some champions need nerfs more like there needs to be more counters in the game.