The poster above is right. Every aspect of your life will feature different social arrangements, and in all of them, to some degree there will be a hierarchy of sorts. They aren't the same though, and they change radically as you get older.
The main issue with this at school though is that pupils are still young, and when your young time stretches and things feel like they will last forever. As an adult if you told me that X was going to be my situation for the next 2 years, then I'd say that that feels short and manageable. But as a kid, 2 years is forever, so any problems you face feel so much worse. Couple that with the fact that teenage brains, due to the way they are developing are far more sensitive and aware of social contexts and you get a situation where the problems feel like they are more dramatic and important, and they feel like they may last for a much longer time.
To a teenagers parents the little drama that their child has with their friends is just silly and will end in a few weeks.. but to a teenager going through it, its the most important thing, its their life, and its massive.
So overall, you can't escape the way social groups organize. It's necessary to have that when your young to get you used to dealing socially with people as an adult. The nature of them change throughout your life and depending on your circumstances, but due to your age and the way your brain develops the social situations you find yourself in as a teenager feel the most extreme and often difficult to manage.