Promos are just impossible.
I win 8 out of 9 flex games and then I get into promos and they are impossible. I'm plat 3 in solo duo but gold promos in flex are impossible. Lose a game because my team does nothing 3 times in a row. Last game I even have my team fighting 4v5 when our only hope of winning is stalling, we are losing but my team just fights for no reason. Not even challenging an objective, just playing aram. My team challenged them a minute after they they took baron!
Get into promos and the game just becomes impossible, Silver, gold and low plat are a cesspit.