It's unreasonable how often I'll be in a match and think...

..."there is literally nothing I can do here. My only option is to give up." Not necessarily the match as a whole (but that happens too often too), but any small detail throughout the match that can push it one way or the other.

Like, "I know for a fact the enemy top is stealing our blue. It's a shame I literally can't even attempt to stop it or steal it because there is a 100% guarantee he'll just one shot me from full hp out of stealth. Better just give up and let him."

"The enemy team has three people coming this way and my team is either dead or doing something else. Better give up, run away and let them have a free turret since there is a 100% guarantee I die from full hp even under my tower without stopping them and they get the turret anyway."

"I see the enemy jungler solo-ing drag. Unfortunately he's a better duelist than me and bot lane is behind so they can't risk coming. Guess I have to just give up and let him get first drag for free since there's a 100% guarantee he'll turn and kill me with no effort if I try to stop him."

Over and over, continuously throughout every game there's the feeling of "no matter how well I play, I still can't do anything;" either because the enemy has even the smallest lead and has started snowballing, or because their Champions are simply more overpowered to the point they don't really even need to play well and can just roll their way to victory. It's far too easy and far too common for the outcome to be decided in a game of League before the fighting (not strategy, strategy is invalid against getting oneshot) can even start. The amount of damage in the game, or the rate at which damage can be acquired (gold income) needs reduced dramatically, or this will be the case forever. It's just unreasonable that an enemy who's up only 1-2 levels and only has half an item more is basically untouchable.