"Whoa is me! Riot/My team/The game/Luck holds me back!"
Meanwhile any diamond+ player can make a smurf and climb a couple divisions a day.
You aren't stuck in ELO hell, you just aren't playing well enough. And no, your positive KDA on Katarina/Yasuo/Teemo/whatever doesn't mean you played well enough.
If you play consistently correct, every game. You rise. Period. You will lose some games, but overall you will climb. Boxbox and others can gain rank in "ELO HELL" while doing dumb shit like Crit Attack Speed Riven. Stop making excuses.
Teammate feeding?
Null problemo, just enjoy the godlike clone :^)