League of Legends is better when you have "a team" (May seem like a duh, but please read)
Over the years i've played. I've seeing now that League of Legends is best played when you have a team. Not necessarily an LCS team but "a team". I think that is part of where a lot of stress is coming from when the game is played. You que with five random people who you don't know, they can be toxic, non-toxic, skilled, not so skilled, etc etc. And going from game to game like that, yeah it can understandably cause a lot of annoyance and frustration. If you think about it, if you have "a team", you will know how they act, how they play, etc, all that will be situated, generally speaking. I've been playing since beta and I'm just now understanding it to his degree.
So, unless you really, really...really are playing casually. Like, coming home and just playing a game to chill, then random queing with five, may not be an issue for you. But if you play with some form of competitiveness, then a team will be what's needed.