Why are the games 1v5 every other game?

garen goes 5-10 to a riven who is trash and mains support. Jungler plays lee doesnt do shit all game. Adc picks vayne (prob shoulda dodged) dies 13x does no damage. And I guess karma was fine besides dying too much. Only one positive completely stomping my lane but it doesn't matter yet again because its 1v5 and pardon my french but my team is literally r%%%%%ed compared to the enemy.

actually now that I look back even the games I won it was me going ham and only 1 other player being useful. Idk this account is legit rigged rofl Ive never had such terrible teammates game after game. It would be one thing if I was a legit stuck silver bitching but im not so its a little ridiculous that 1 game in like 20 I have more than 1 player on my team doing well. If I was a real silver player I would probably be bronze on this account rofl. No game would be winnable besides like 2 of them.