The 1100-1200 range is the absolute worst range to be in.

I think its around 1100-1300 where its very mixed between serious and non-serious players. For most people 1100-1300 may be the highest level they can reach while playing casually (Not studying, analyzing, or anything of the sort). So either they continue to be casual and stick around here for a long time or is getting ready to be serious and improving themselves. Of course, the serious ones run into each other as well so its not as easy to get out of that rating even if they have already improved.

I've been casually playing and doing daily puzzles and have been siting around 1050-1150 for a long while which seems fair as I don't study, review or anything and someone I know said to go above 1200 you really need to start to study and do more investment. Just the other day I hit 1200 and I was like woah that's wild and then I shot up to 1300 in a day with some of the easiest games I've played in a long time. I'll probably fall right back down but feels like something is wrong once over 1200

The progression from 1200-1700 mainly involves learning about chess principles, not so much studying specific opening lines. So these are things like tension, tempo, space, pawn structure, piece activity, etc.. Knowing openings helps but I don't think you need to know them too deeply, mainly you just want to be playing positions consistently so you start to pick up on the tactics / plans of those positions.

Tru/

Technically the worst range to be in is 1600-1800

I am honestly 1500 Rapid 1300 blitz I think 950 -1100 is a worse area. I tilted a good while back. Just kept playing and ended up down around 900 Scheese it was rough getting back above 1000. My blitz ceiling seems to be like 1300. I've been 1300 as last night. But I get several messages from support awarding me points back. I'm sure you all know why. The people that use assistance to take points from honest players is the scourge of the game and this site. Penalties need to be more severe and permanent. Because whatever the penalties are now isn't working.

I'm stuck in this range, and I hate it. I've basically stayed in the same place for the last two years. If I go through a long losing streak I'll dip below 1100. I've been fortunate to be above 1200 for a few days.

AND I DON'T KNOW HOW TO BREAK OUT OF THIS.

I solve puzzles. My puzzle rating is above 2200. I'm pretty decent at openings (Aimchess says I tend to come out of the first 15 moves either even or with a slight advantage with both white and black). I don't know what to do to get to 1500 - and beyond!

1200 is elo heaven... I hope you are winning

Playing with a goal to reduce errors rather than aiming for brilliance can help you stay grounded through these swings in opponent skill.

Chess is cool

I am one of those 800 blitz 1100 rapid players. I only rapid when I have time, but I play blitz at random times during the day when I don't have 20 minutes to set aside. So I think its just about how good people are at making decisions quickly.
Those 1600 blitz players you get probably don't take their time at higher time controls and we 800 blitz players struggle with making quick decisions.

Are you serious? The 1100 - 1200 range in rapid is absolutely the worst. People in that range know most of the opening theories and even know some gambits or tricks. I could go down from 1400 to 900 easily. Then struggled to climb back up to 1000, then 1100, and then 1200. Then went back down again to 900. Then climbed back up to 1000, then 1100. Then fell back down to 1000 again and then 900. Then climbed back up to 1000. Recently, I kind of gave up playing real players and just played bots. I could beat the 1500 bot most of the time. I can beat the 1800 bot 50-50. I mostly lost to the 2000 bot. But I did manage to win 2 games against the 2000 bot. I just climbed back up to 1200 playing real players. When you play against players who are better than you, you know you are under more pressure. The pressure I am facing constantly increases over time on chess.com, even though I am playing at about the same elo range. 900 - 1300 in the past 2 years.

🙄 If you stuck it's not about which elo range is the worst 1200s know just enough to see some tactics but NOT to play openings correctly and NOT to avoid blunders by move 5 1600 isn't so bad but 1800-2100 is switching from tactical play to understanding a tiny bit of positional play to but if your stuck it's not your opponents and 1000-1300 rapid is just 800-1000 blitz :/ ps:everyone gets tunnel vision even 2500s

I think your at the range where people start overestimating their own strength and the strength of their opponents which could be part of it

Quoting is not working cortectly:/

if that keeps happening just type like "------" before you start writing so people can find it better

I call it the ten second range. Basically, if most players in that range would sit on their hands and not react instantly and just take ten seconds more, they'd probably play 1500. 
I should know. I'm below that range, yet when I take my time my games appraise at about 1600 to 1700.
Pacing myself is a major problem for me. I perform a lot better when I do. That seems to be the main thing keeping many players in that rating range. They do well then blunder in some games, then take their time and the next game is a massive improvement. 
It's a discipline thing and when you play computers and they just move instantly, the tendency is to be the same. It gives you bad habits.