How do I win when my teammates die as fast as possible

I have over 400 hours in the game and play for fun and I try not to flame others BUT how am I supposed to win any games when my matches routinely have 1-2 people throw themselves at the enemy and die as soon as they are up? I feel that it is impossible to win due to the team just being able to do mid or urn and snowball off 2 mindless players. I try to play carry characters to counteract this but sometimes it just feels like a roll of the dice if I will get breathing humans. Low archon