Who taught you statistics? Ask for your money back.
Feeders / Trolls / AFKs / Whatever else are assumed to be in lower ELO brackets because they lose ELO for their actions. That's why upper brackets don't see them much, fine that makes sense.
Sub 1500 ELO you start seeing people who have the ability to play or not feed, but also maybe don't want to be in the higher ELO brackets because their win/loss record goes to garbage. Much easier to play people in lower skill profiles, so these people who intentionally reduce their ELO exist somewhere in this region. (Lose a few games, play people who suck, come out net positive on win/loss record with little or no net change in ELO record). Then below that you have the rest of the garbage. Starting out with a win in a fresh season might get you around 1200-1300 ELO ranking. So here you see a lot of garbage while ELO stabilizes, this contributes to why not all garbage players exist in low ELO standings. Example: I have an account with say around 450 Normal wins net positive say 20 games over losses, I then play my first ranked and happen to win now I'm ranked 1280 ELO - that doesn't mean I'm a 1280 ELO player. If that was my first ranked ever I'm really probably a 1000 ELO player, but I'm going to play a solid 15-20 games before my net losses bring me to correct levels (some players will carry this account in ranked and happen to get this account some wins along the way that they probably don't deserve).
No combine these types of players with the normal trash of AFKing / Leaving / Trolling / Whatever else, and you have a big pool of nonsense that you can get paired with. For example purposes I'm just going to say it's a 15% probability of getting paired with one of these players in the 1000-1499 ELO pool bracket. A 1600 ELO player goes on a losing streak in fair games, dips into 1300 ELO territory. They have a 15% probability of getting knocked with a bad player, 85% of the time they are not going to have a problem and so they win games and get back to their normal ranking 15 or 20 games later. They then go on the forums and claim no foul with ELO Hell.
Take the 1000 ELO player who has no spent a couple months getting better with skills and is now 200 ranked games in at 1100 ELO. This person has lived their entire ranked career bouncing in the 1000-1499 ELO bracket, constantly pairing with the higher probability of being paired with bad players. The probability a high ranked player gets hit with ELO hell is diminished significantly the higher the ELO they go. A ranked player who lives in the 1000-1499 bracket all day every day they are eventually going to get probability tipped against them. They get burned either between fair games or unfair games down to 1000, they have to span 500 points of ELO to get some serious diminishing returns on pairing with garbage players. It is unlikely that this player will go that many games in a row with fair gameplay in this higher probability bracket. So while a player may indeed get fair games more than 50% of the time in this bracket, it is unlikely that they will be able to get that probability in their favor enough times for them to exit this bracket.
What is even more depressing is that if probability runs against you more than once in a row, you fall into a pit that becomes even more difficult to get out of. For every 1 ding against you, you need two to get out. This multiplicative effect means that you end up having an even higher probability of getting sucked back down than you do of getting out regardless of skill level (you have to constantly be the equivalent of two players in order to compensate for one bad player in order to overcome this probability, and forbid you end up getting TWO bad people in the same game on your team, then it doesn't even matter anymore). Assuming everyone else on your team is equal minus the one bad seed, and everyone on your opponents team is equal that 2 man equivalence also still does not hold true. Feeders turn bad opposing players into formidable players just because they outpace you so quickly in gold. Skill becomes irrelevant when a Singed can tank 5 players and two towers doing nothing but right clicking randomly around the screen just because he's 4 levels higher with 4k more gold than anyone else on the map, purely because he was solo top against an intentional feed Kat with 6 mana crystals.
IF YOU READ NOTHING ELSE, AT LEAST READ THIS PARAGRAPH In simple analogy: at 1700 ELO, you deal with 1 griefer and not deal with another one for 10 games. At 1100 ELO, you deal with 3 griefers in a row, then 3 games later you deal with another 3 in a row. Whether they're on your team or the others is irrelevant because it takes two games for every 1 poor game to go net positive ELO, and in THAT probability it is less likely for you to advance because probability says you will get a garbage player that you will not be able to compensate for on your team faster than you will exit the probability bracket to where this is not true. This is the math behind what people refer to as ELO hell. Yes some people are lucky enough to exit this bracket (It's a lottery after all, there are some winners), and those people who are lucky enough tend to be good players because good players have a higher probability of exiting than bad players (bad players who win the lottery will self mutilate themselves back down, so their fair games are moot) BUT THAT IS NOT EVIDENCE THAT THE SYSTEM IS FAIR - which is the annoying thing that I hear these players claim. The larger population of good players will NOT win the lottery: The ELO Lottery pool is stacked against them.
To say this stuff doesn't exist is ignoring facts, not opinions. Pictures, videos, statistics have been posted (mine have been deleted by Riot for unknown reasons). I've gone not just a few games, but multiple days in a row without getting a 5v5 fair match in. I've had multiple games where people flat out say they will troll the game in character selection just because they don't like someone in the game because they disagree on some trivial thing, even unrelated to the game (once it was because one was a Republican and another was a Democrat! Why is that justification to troll a ranked game?) Imagine trying to dig yourself out of that pit?
Note: Before some idiot says it, I know 1100-1499 are made up ELO bracket numbers. I do not know the true place where "ELO Hell" exists, I am just picking numbers for example purposes. If I had access to Riot's database then it would be easier to pinpoint where it exists. Ever wonder why ranked stat tracking on outside websites stopped? When this happened it became impossible for outsiders to find anomalies.