League of Luck - Soloque Supports

League of legends soloqueue is almost entirely RNG dependent for some unfortunate souls. I climbed Gold 5 to Plat 5 in about a week no problem at all. There were a few losses, don't get me wrong, but a 10 and 8 game win streak were involved, so overall the experience was rather simple. However, Plat 5 is a very different story. As a support main - unfortunate soul mentioned above - the game is quite unkind to us. If I lose the game, it was because I was unluckier than the enemy team. I hear the complaints already:

"But it's not luck bro, it's pure skill and you aren't carrying hard enough from support as Janna."

I'm not claiming perfect play by any standard, but I am claiming play that consistently beats diamonds in normal queue whenever they're around be it vs me as a jungler or as a support. Here's the problem: my lane isn't a losing in any of the games. Literally none. At worst, it's a 0-0 farm lane for laning phase. Things go downhill when I look at my jungler who's 1-4, mid who's 1-3, and top who's 0-7 (numbers from a legit game) and bot lane is 2-0. Okay, I played correctly. I played well. The rest of the team fed and there's nothing I can do about it. Game's over, we end up losing.

I do want to mention that I am not negative with my teams. I always break down in pregame what our win condition is, what to avoid, cheer on lanes when they get kills, push for good decisions about when to split, objectives, etc. I roast in post game for throwing a game. Supports have far too little say in what happens outside of laning phase because even in games when the ADC goes 10-0, a fed enemy team will slaughter the squishball in a few seconds. It hardly feels fair to, as nightblue says, "play to improve, not climb" and be constantly punished for proper play.

Additionally, I've noticed a difference in attitude. In Gold, I'd ping and essentially tell everyone what to do and think for them - but they'd listen. In Plat 5, everyone's a challenger tier player who knows everything about the game from matchups to strategies and refuses to acknowledge back pings, warnings of enemy jungler placement, etc. I always call summoner spells, I call objectives, I call every time I see the jungler so everyone knows exactly where he is every moment of the game, but I don't see anyone else keeping track of the game. They still manage to die to him even when I outright say "Kha is coming up on mid from bot river". These childish players have ruined so many games to the point I don't feel like playing ranked at all anymore. It's outright not my fault for losing when the team feeds. And do keep in mind I am honest with myself. I look back every game and say "What did I do wrong?" "Where could I have done something better?" and routinely the answer is not much in these games when there isn't much I can do other than drop wards and hope the enemy throws.

TL;DR - It feels unfair when you lose because the team fed and you played well.

QUESTION FOR COMMUNITY: What can be done other than switching mains to a carry role and throwing the team on your back? How can you overcome legitimately bad teams as a support?

I appreciate everyone's time and responses. Any additional details you're curious about can be provided and I wish you all the best in the League of Luck.