The enemy team actually has the following things:

Tldr; Believe it or not, the enemy team has inters, trolls, afkers, players with bad games, toxic asshats, and every other type of degenerate that most League players hate having as a teammate.

So I see what feels like 10-20 posts a day about players complaining about their teammates. They cry they had trolls and lost promos. They had 1,983 afk teammates today and got demoted all the way to clay VI. They had someone who went Nunu smite/not-so-support which sent them on tilt and caused their computer to crash mid-Baron attempt and now they got Leaverbister for 5 years.

Ok, maybe that last one is a bit of exaggeration, but the point is, so many people cry all over the boards about their team/teammates and how they cause them to lose over and over. It would actually be humorous except for the fact that I must wear waders to get through the sea of tears left behind.

But guess what... The enemy team that you just beat, is dealing with the same exact thing. Players seem to feel like it's a one-way street, but it's not. There's cars on both sides of the road. The enemy has to deal with shitty teammates just like you. Don't believe me? Watch the flame session at the post game lobby in a game you just roflstomped the other team. Watch that level 6 jungler that went 0/1/0 30 minutes into a game.

So yes, at the micro level, you may have lost a game because you have some sponge of a teammate who gets mad and then decides to drool his way down mid to a 0/22/0 score line, but you may only have gotten to that level because you had games where the enemy decided to put a lawn chair out in the fountain and watch the world burn.