I was in the Canadian education system until grade 4. I learned material in Canadian grade 3 that was not taught at all in US public schools, or wasn't taught until grade 9. The system in Canada had cliques, but in general we really were in school to learn. Things were taught, we learned them, it wasn't perfect but we were there to grow. A big part of this was emphasizing that learning how to grow on our own, to explore and understand new things. I think a lot of this may have been because of the age I was at the time, but it felt profoundly different.
The US education system was....sad. You weren't really there to learn. You were there to take tests and pass on to the next material. Your successes trivialized by the volume of substance-less obstacles you must overcome to continue. The pacing and feeling were so different that I almost immediately lost any interest in school. To start with, I didn't really get the opportunity to catch up to my 3rd grade education until fifth grade. Sitting through much more slowly paced, rigorously tested material that I'd already covered was horrible.
That's a lot of what the US school system is, and that only got worse as we progressed in years. In grades 5-8 my state was re-doing their proficiency testing system, so I had to take the same thing a couple of times. It was massively overhyped and touted as being a life-ending test, but really only covered material that was the basest level of the education we'd been exposed to.
e.g. "Who won the Battle of Bunker Hill?"
Answer: The British
A brief review of this battle reveals to the reader that while the British did win, that wasn't important compared to the actual battle itself, the conditions leading up to the battle, the consequences of the battle, or almost any other factor.
So, second or third iteration of this testing in 9th grade I pass my Proficiency Exams with "Above average" markings while putting forth no effort whatsoever. We didn't get scores, just above average, passing/average, and fail/needs improvement. That's helpful. In a system with 3 outcomes and about a minimum 25% correct rate, I scored in the top 33% or at minimum 42 points above failure. I know now that those numbers really aren't right, but as a kid I just kinda guessed and figured that wasn't too impressive.
Passing the big test in 9th grade meant that unlike half or less of my other classmates, I was going to graduate as long as I showed up some. Knowing I was going to succeed and still having to attend for three more years caused an ache for freedom I imagine is much akin to the emotions that prisoners feel.
The social interaction in school bordered on the stereotypical clique structure. The Haves considered themselves the most popular students and attempted to lord over the other students with manicured clothing, flashy hangouts, and eventually fancy phones. The Wish-they-were-haves were largely slightly less well-to-do children who tried to emulate the Haves and usually succeeded only in making fools of themselves in the attempt. Then there were the band/choir/theater geeks, who clung avidly to being band/choir/theater geeks while absolutely nobody outside of their group cared at all. It wasn't about money or status, so the people that cared about social cliques didn't care that they were in band. The rest of the school was divided into students who really didn't care about the previous 3 cliques, and often intersected with members of those 3 cliques per the general fluidity of social scenes in high school.
Aside from that system, there was another one based on interests, extracurricular activities, and aspirations. Like anime? There's a group for that. Like football? There's a group for that (aside from the football team). Like having casual sex with below average to awful looking people? There was a group for that. They pretty much all fucked each other or pretended they were, but it was generally felt that there were as many lies as truths.
Most people just hung with a small group of like-minded individuals until they changed their motivations and hung with another group of individuals. As teenagers are, there was an incredible amount of people being horrible to each other. Fights, rumors, anger, and in smaller doses kindness.
Unarguably the most popular girl in school earned her position by being one of the kindest people that anyone could hope to meet. Her family was wealthy, she worked hard, and was kind to everyone. She dated four guys in high school, one from the football team, one from the Haves, one from another school, and a quiet bookish dude that mostly just read books instead of talking to people at all. We didn't have a most popular/guaranteed prom king kind of guy.
The interesting thing about the social aspects of school for me was the bullying. Up until about grade 8 bullying was common. X, Y, and Z picked on A, or B, or C, with concentrated annoying for a week or three at a time then rotated targets. By the time 9th grade/high school rolled around that shit basically stopped. I entered into HS shortly after the Columbine shooting, and it had a pretty solid affect on all of us. If you want to bully people, some good Samaritan is going to come to the defense of the bullied kid and beat your ass. The kids that had been bullies would try and pick on the kids they had bullied, and get a solid beatdown from two or three random passersby. This system worked so well that the only bullying that took place had to be more sly and well crafted. Band/choir/theater ended up being the place with the most psychological torment, but since it had the dark/goth/emo kids in that group it also had the most false outcry.
Towards the end of my HS experience, a pair of kids died by doing some extremely illegal, dangerous, and stupid stuff. About half of the school and probably less than 30% of the teachers acted like it was a huge deal. The rest of us felt that if you load a gun, point it at your face, and pull the trigger, you should probably expect to die. So two new meta-clicks were born, the perpetually-seeking-counselings and the don't-give-a-fuck-but-woo-no-finals! groups.
All the while, the education groans on. Designed solely to keep us there while we wait for graduation. After I graduated, the IB and honors programs kicked in, tech/trade programs kicked in, and local universities started offering college credit programs. Well gee, thanks. That would have been nice!
So...there's truth, yes, but in the way of a grand tale started from a small deed. It probably is much more segregated and factioned in other schools, but in mine it was more fluid than 90210 or Mean Girls.