I feel like your logic is faulty.
You've taken two accounts through silver, there must be no problem in silver.
Now, perhaps I agree with you. I've gotten out of silver two seasons in a row, and will do it the third time.
Now perhaps I don't. I had no difficulty whatsoever getting out of silver the first two seasons. This season I got placed in bronze 1 and it took me more games to climb to silver 5 than it took me to get gold each of the prior two seasons. Then I promptly have climbed to silver 2 promos in less than half that many games once I got out of bronze.
Playing from unranked, getting to gold is quite easy with a few decent teams. Even top 40 percentile luck would get you to gold rather quickly. 40% squared is 16%, so there's a 16% chance you're a garbage silver player like the rest of them and you just got lucky twice.
Don't get me wrong - I don't really believe that. To say your own experience invalidates someone else's is pretty ignorant though.
First - I think the real thing is that there really isn't a big skill level difference between silver and platinum. I play with platinums, diamonds, and even the odd master/challenger tier player in normals. The platinums are typically no better than golds, and I typically beat-down my plat lane opponents (and promptly get smashed by their diamond 2 jungler or other laner). I get platinum borders in my ranked games and they typically do worse than the gold borders do (I've stopped checking all players ranks before my ranked games, it sets me off), and have entire games in silver where the decision making is sublime while games with all plat borders make unbelievable throws. So is there a difference between diamond and below diamond? Sure, I really do believe that. So just because a diamond player can get out of silver, does that mean Elo hell isn't real? Maybe you need to be Diamond to be able to do it easily, and even a Plat level player could get unlucky enough to be stuck there for 400 games.
Second - you've already argued it's because his champion is bad in the meta, etc... I don't believe this argument for a second. High tier players often argue that it's "so easy" to carry in silver/gold that you can play any "insert non-viable champion here" with "insert even worse build here" and still carry. If it was really true, it wouldn't matter who you were playing. Even though it's not true, it still doesn't matter. The game really comes down a lot more to decision making and knowing how strong your team and the enemy team are, so much so that a better player will do better even if on a non-meta champion. To quote my own experience again, I've simultaneously done fine (>55% win rate) playing normals with the average rank in my games being low diamond and losing (<45% win rate) in silver ranked. I've won top lane against a challenger one-trick on his main while a diamond teammate was winning lane against another challenger player in mid lane (then when they were each 0/2 they lane swapped and promptly spanked us - I'd like to blame it that I had already built a chain vest and suddenly was against an AP opponent but really, I'm aware that they just out-macro'd us) and then the next day played the same champion and went 0/4 in lane to a high silver player. Thing is - silver players aren't consistently bad, they're inconsistently good. This adds even more to the luck element, because if your opponents are on an "on" day they can hang with diamond players, and if your allies are on an "off" day they can feed to silvers.
I would say third but I feel like my argument has lost structure by this point. All I'm trying to say is that you can't really judge things on individual experience. You can see mistakes people make, fine. I watch challenger streamers and see THEIR mistakes ALL THE TIME. That doesn't mean they're bad. It means they make mistakes. It's VERY easy to see mistakes when you're not concentrating on playing. I watch plenty of high challenger players walk over a ward or walk where I've noticed an enemy placed a ward previously then get piled and comment "oh there must have been a ward there". Of course there was, you SAW THEM PLACE IT! But you didn't, I did. A gold elo player saw it but a challenger player didn't. It doesn't mean I'm suddenly better than them, it means that when I'm not worried about dodging a skillshot in lane and landing my own and having favorable trades and last hitting I can pay more attention to the map. I can see that the enemy jungler just showed bot lane as you top lane stepped back from a certain kill and said that you think his jungler is probably nearby and he's baiting you. I don't suddenly have better map awareness than a challenger player - I'm able to see it better because I'm not in the game. Likewise, you're seeing a lot of mistakes in silver because YOU'RE NOT IN THAT GAME. And if you're watching in spectator mode you're also seeing information they don't have - you see the enemy team's vision, etc... and that makes it even worse.
In low elo your allies make a LOT more mistakes. That makes it harder to carry. Even if you make fewer mistakes, that doesn't mean you'll be able to carry your allies mistakes. I've watched enough "unranked to diamond" or "unranked to challenger" videos to see these very high ranking players (who DO get to diamond / challenger on these new accounts) lose games in silver/gold. They go 8-2 in placements. Why are they losing 20% as a Diamond 1 quality player?? Doesn't that mean a platinum 2 quality player could feasibly go a while only winning ~50%? It really comes to grinding enough games just to make luck not matter and the small difference in skill really count.
Role selection also really matters. Thing in low elo is that it's WAY easier to carry mid lane or jungle than anywhere else.
Top lane if your opponent picks a tank he can choose to not feed you if he notices an ally is going to carry. You can't do anything.
Bot lane you're dependent on another player and if they can't play correctly at all you'll lose. Even if your the ADC and you out CS like mad, if the enemy ADC gets a kill on your supp every 2 min it won't matter he'll have similar/more gold and definitely more XP from the kills. If you're support you can set up loads of kills but if your ADC can't last hit for garbage it won't matter and the enemy mid that's ahead can roam and get juicy shut-down gold.
Mid and jungler get a lot more map presence that makes it easier to carry in low elo. They can capitalize on mistakes much more easily (and they can target champions that are punished for mistakes while playing champions that capitalize easily).
I'm writing a lot, but I hope I've made you at least consider some of these things. I really don't believe elo hell exists, I just think that there IS a luck element and there's a game threshold to overcome it. With decent luck you'll get out of silver in 10 games if you're highly skilled, or maybe 100 games if you're high gold/low plat level. With poor luck you may get out of silver in 50 games if you're highly skilled and it could take 1000 games if you're only a bit better than silver. You need to put in the games to get there. Those numbers also depend on what you play and other factors - but predominantly just how much better you are and how lucky you get. A player who's low plat level could definitely get stuck in silver for a few hundred games - it wouldn't be an extremely unlucky scenario. I wouldn't call it elo hell - but it'd be very frustrating.
