ELO is the measurement of how long you're willing to play this game and how lucky you are in matchmaking, at least up to a certain point.
Up until 1800 or so. I don't remember the exact number. Plenty of streamers and friends alike have suggested/agreed - Elo is random from 1100 to 1600. The only difference is above a certain point you stop getting those players who completely feed and have no idea how to handle a lost lane, and it makes it easier to carry. The average skill level of players remains the same.
Also the concept of "if you are truly more skilled than your ELO you will win on average." doesn't always ring true. If you are "truly" 1400 in skill level, and playing at 1200, and you get laned against the guy who is "truly" 1800, what is there to be done? This game does not have such a high skill cap that you can just outplay everyone at your elo, it doesn't work that way. Sure a high elo player can carry any low elo game, but they're 2k elo players or higher. In their situation, they're basically the 1800 playing against the 1400 in a 1200 game.
I hope people know where I'm coming from because I feel I didn't word everything right. Basically you can lose games regardless of your skill level, and especially early in the season or around the 1100-1300 bracket with new players rushing in, elo has always been random. A toss up. Unless you're *very* skills (can carry yourself 1600 or higher) it will take you hundreds of games to gain significant elo, and you can lose it in a matter of days with bad luck.
Another concept is the concept of character elo (BP vs PP in Street Fighter comes to mind) and I bring it up in every elo thread. I can always carry as Ryze or Varus, my Ezreal mechanics are decent, I like the play style of Ziggs, however whenever I play Jayce I win lane lose game because I am just not skilled enough with him yet. However I love playing the champ and always feel like maybe this is the game I can carry. I'm like 40% with him even though I don't believe I'm *bad* with him. If I truly wanted to gain elo I would just grind Hecarim/Ryze games all day every day (Athene lol) because I only have 70%-ish percent with those champs at various points.
Many of the people in your ranked games might be 65% on Lee Sin top, yet he locks something like Renekton first pick top to try him for the first time and gets crushed by a Kayle. You could even have someone who only plays a mid like Ahri (70%) but no one was willing to trade, and he picks and has to face a Kassadin or a Talon or something. You could have your bot laner get fed due to your ganks/support but then lose anyway because they can't actually position well in a teamfight.
You can have the best mechanics on one champion in the game (Cris on Riven, Inverted Composer on Singed come to mind) and play only those champions and carry yourself to top tier, but there's no question you have lower skill on many other champions and will, on average, lose your lane in any other role.
Plenty of things can happen that keep your Win/Loss % roughly 50% regardless if you're 1100, 1200, 1400, or 1600.