Ranked, why?

You know, I know this gets said a lot, but why is it in ranked, specifically when you are in promos, why are you so much more likely to get afks, rage quitters, trolls and feeders? Last two games, first one bot lane had a huge arguement that resulted in our support (blitz) afking and our adc (varus) to intentionally feed. He didnt want to play anymore and made it even worse when decided not to surrender. If riot is so strict about this toxicity being punished, then why is it so prevalent?

My last game, support picked Lee for support and built all damage after losing lane. Ezreal was raging and flaming the support, all the while me and the jungler had 6 kills and 0 deaths between the two of us, we were doing well, i pinged whenever mid would roam and even ping bot to back off, and they would dive in. i can win 5-6 games in a row, then just straight up lose a series to games like this. I know i still make mistakes, quite often but I try to learn from them, This same thing happened last season when I was in my gold promos. I was in my promos for gold no less then 5 times. lost every series. I didnt get an afk or a feeder every game, sometimes you just lose, which I am okay with, but it just always seems to be that whenever its down to the last game, or when it matters the most, the worst tends to happen and it doesnt matter how well you play, you cant carry a team that doesn't want to win. I understand that i made mistakes that last game i was in, i ended like 5/2/2. It just seems so much worse because it feels like the tiniest of my mistakes are so much more impactful because of the bad play by the other lanes.

Ugh. Tilted.