It's also important to note that when your team is uncooperative, the enemy team has the exact same odds of being uncooperative. Over time, the occurances where you get a troll/leaver/afk/lag will be even to the times your opponents get a troll/leaver/etc.
The system doesn't discriminate, and people aren't specifically trolling only you unless you give them the reasons to. And games with trolls and afks are not unwinnable if you know how to talk, and you can back up the talk with good play. You can't change how your teammates or your opponents play, but time should even out the effects of luck, and if you're a truly good, non-toxic player, the odds are actually stacked IN your favor to win more often, solely because, assuming you are good and nice, your team has 4 slots for bad players while your opposing team has 5.
So if luck evens out, even slightly in your favor, the only feature that you can use to influence your game is your own attitude and play. I win 2 games on averave for every loss, and a lot of it is because I do everything I can to win, even if I mainly play support. I've carried lanes so that my adc gets big through my work. I've warded lanes that don't ward often enough so they die less from ganks. And I've stopped toxic players from dragging my team down 3 out of 3 times they happened. I've stopped a trist from trolling as adc, stopped an ap corki from afking, and stopped my entire team's infighting to push our advantages to win. Even with toxic players, the right approach can win you a game. Every game is winnable until your nexus is destroyed. Or in the immortal words of scarra: "(you're) winning the games until (you) lose it."
So suck it up. Team cooperation is a factor of luck that evens out over time and a neutral disposition. Luck always evens out with an average player, only what YOU do influences what happens to YOU in the long run.