Recently experienced it a lot in solo queue and rarely in duo queue also. The guys in opponent team are trying hard to win the comp game, on the other hand there is my team where the randoms are not serious. I mean I am fine if we loose but...

My friend, who I barely play with anymore cause of this, always leaves his comp games. He leaves every time he gets tilted, or a teammate of ours gets mad at him. I haven't been playing with him, but he still does it when we're on discord....