Believing you're silver 2 and actually being silver 3 isn't a big difference. This has nothing to do with "elo hell". You may or may not be silver 2 level. You may or may not be silver 4 level. The skill gap between silver 4 and silver 2 isn't substantial, at all. I guarantee over half of the 9 people in your game all believe they belong at least 1 or 2 divisions higher than they are (if not more) - yet all 5-10 of you are where you are.
That person who had a bad game at silver 2 and went 0/5? He thinks he's gold level. The guy who went 5/0 when his team was 0/14 also believes he's gold level.
I've hit challenger solo queue on two accounts and had multiple D1 accounts. I've been on the rank 2 challenger 5s team and played in NACS qualifier tournaments. Guess what? I've had games in solo queue and 5s where I've gone 0/9. I've also had games where I'm 23/2, in the same queues with the same exact players. It happens to each and every person, at every elo, in every queue.
Not every game is winnable. Are you going to get bad teammates sometimes? Yes. Are you going to be a bad teammate sometimes? Yes. I've lost a normal game as Kha where I was 56/2. 56/2 and I lost (my team had 3 total assists, I wish I still had the screenshot). I've won a game where the enemy Vayne got a quadra kill during a lvl1 invade. I've also won games where I've been 0/13 in solo queue.
You've carried players, just as they've carried you. Everyone has bad games and bad days, it's just much easier to recognize other mistakes and mitigate yours. It's much easier to blame your teammate for not following up than manning up and saying "you know what, I shouldn't of even initiated that fight in the first place".
Of course, people lose because of there teammates a lot. There's something like 27 million players who play on a daily basis. That's room for a LOT of shitty games and a lot of good games. Personally, and I believe this true for a lot of others as well, when I have a good game (whether it's via my gameplay or just an overall good experience with my team) my initial reaction isn't "lets post on the forums about it!" - it's "I really want to play again". Rather than posting about it, I'm going to just play and ride my "high". I don't post when I have bad games or bad teammates, but I'm certain people are far more inclined to complain about their team on the forums than post when they got a good/decent game. You have to take into account sample size and prejudice, which unfortunately nobody does.
Elo hell does not exist. The system is working perfectly fine. Are you going to be exactly where you should be in 10 games? 50? 100? No. Maybe not. But over time, you will. Like I said, if you deserve silver 2 but you're silver 3 it's going to take time to get there since you're barely better (not taking into account the other s3 people that deserve s2) than the players you're with. On the contrary, if you're a diamond player playing with silvers, it'll be a cake walk barring extremely bad luck (which isn't consistent, at all).