Flex Placements reset not helping at all

This was my last chance to improve my flex rank, and I get a 0/13 yasuo who feeds to a Nunu mid lane. Meanwhile, there was a 15/6 Jinx who tried her best to carry. People like Jinx (or me) are getting screwed over in our last game to improve our flex ranking before the season starts. I don't think that the way yasuo played represented Jinx's skill level, or mine even if I lost lane. I believe that our team could have won if yasuo didn't go 0/13, but we were unlucky. Giving us one placement game does not fix the flex placements because it just boils down to luck. Please give us more placement games riot, my rank shouldn't be dependent on how lucky I was on that final game.