If you never learn how to play while you're behind, how do you expect to climb? I may not play a huge amount of ranked games which is why I'm only just about to hit Gold, but of the 16 games I've played recently, I'm steamrolling my way through this low elo and currently sitting at 13 wins for an 81% win ratio. Some of which were even 4v5s where my own teammates intentionally ragequit. If I had listened to those nay-sayers and forsook my own ability to carry those games, I'd be sub-50% winrate. That's because I can often force a victory even when we're behind. That is called carrying a game.
Carrying a game doesn't mean the score was 20 vs 5 with no one on your team feeding. You weren't required to carry that game! That game would've been won even if you were 1/2/1. There was nothing to carry. Carrying a game means it was 13 to 20 with multiple people on your team being behind but you were efficient enough to turn your own individual score of, say, 6/4/3 into a victory against more fed opponents with less fed teammates because you played better, not because you all happened to get fed. That's what it means to carry a game.
Yes it matters who's got the bigger stick but it also matters who's holding it. Most people choose only to focus on how big their stick is, and that's why they suck. Hell, lots of Silver players have hit 85-90% combat efficiency with their main. Mechanically, they're on par with pros. So why are they Silver? If you can't see how you can improve anymore then it's quite possible that you may have actually mastered combat. The issue is that combat is one of like forty different aspects of the game, and if you have to blame teammates because you can't even conceive of your failures in other areas, that means you're probably egregiously ignorant of them. You shouldn't see that as a bad thing though. You should see it as a shining beacon from the heavens. You felt stuck? Like there's nothing more you can do? Fear not! Look at all the other non-champion-combat things you can do! It's not a wall, it's a bridge! It's how you free yourself from elo hell.
Or I guess you could flip that coin every 15 minutes and eventually land Gold 5 by chance after 400 times, then never play again until the season resets to ensure you keep your Gold border.