LoL is a competitive game and all competitive games need some form of consistency otherwise they cease to be competitive. Right now LoL lacks consistency due to one key aspect: Hitboxes. More often than not you have no idea when a hitbox is going to bug out on you, either hitting you when it shouldn't, or missing despite being totally on target. Not only does this ruin the competitive element of the game, but it's also extremely frustrating to the players. Any game designer worth his salt knows that if your game constantly breaks or changes the rules that you have set for it, the game itself becomes very punishing and unfun to play. One of the reasons why the souls games are so popular despite their difficulty is because they are fair. The rules stay consistent at all times and the NPCs follow the rules all the time.
Please Riot, I beg you to try your best to find out what is happening with these wonky hitboxes in-game, particularly when it comes to line-based skill shots. It's no fun at all having the game make you think you have dodged a skill shot only for it to magically hit you. I've been playing this game since season 1 and although wonky hitboxes have always been a problem, it seems like the problem is getting worse and worse over time. It seems like every match I play I get hit by a skillshot that was either out of range or should have outright missed me.
It's not fun, it's not fair and it invalidates the competitive aspect of the game.
Edit: I've done a bit of digging and found the following video
Explaining somewhat why the hitboxes are so wonky.