Choose a lane, split-push endlessly and farm jungle camps, and avoid your team. If your team is good enough to win, you will be farmed up enough to make the difference that wins the game. If you're team is utter trash, which is the more common scenario, the game will end much faster because you're not there to help stall.
Calling for surrenders when your team is full of feeding apes is a waste of time. They will always insist they can win while still feeding their asses off. If you're usually the best player on your team, that is to say, you are somewhat strong and have a brain, your absence makes a huge difference in how quickly a game ends. A feeding team gets instantly steam rolled in team fights without their best player there. And usually the enemy team just rolls over everything until they kill the Nexus after killing your team.