I've been placed in gold every season I've played, low gold last season mind you, but I've been paired with some of the worst players and a couple of good ones. 5:5 win:loss ratio is my current season, giving a 50% winrate which usually places around gold every other season. (47.06% last season looking it up.) Even so, someone said they were placed bronze 1 after a 7:3 win:loss. This year I got placed Silver 4. Not that I mind having to climb, it's just, something about the flex has created a really bad feel to anything ranked.
It's not healthy.
Now, to paraphrase as I understood it:
"It's not the amount of games you win, but which games you win."
That implies that there's some games weighted heavier, especially in placements, which explains the disparity, but it doesn't explain why games won against a higher-end opponents don't raise you more. I've queue'd for Mid:Support every single game and gotten put support EVERY SINGLE GAME. Okay, I'll deal, but an S and A rank every game also don't factor into the rating even if you're playing support. Which means only the win or loss is counted toward your placement. According to some of my match history, some of my won games are against diamond and platinum teams and losses often had lower-end players on my team. As my role is support, I'm not usually able to switch builds and carry. Given the disparity of teams, is it not expected that you might not win with a bronze 5 and silver 3 on your team feeding against diamond and platinum players? Why would this game bring you down so much by comparison?
Where's the ranking leveling out here?
Maybe my data is just wrong looking at other player's histories in ranked, but if I'm correct then Flex queue is definitely not going to be okay in any sense of the word.