The education system was designed in the industrail revolution to prepare children to work in factorys. The world has changed a lot since then but the education system has stayed the same, which means it is not preparing you for life after school like people say it does (unless you are living in the industrail revolution which if you are seeing this you are not).
As a student Your day is controlled by a timetable and not by you, You do not get to decide what happens in what order. However outside of school there is no timetable controlling your life, even in most workplaces there is no timetable and you are assigned tasks at random if you dont get to pick. Timetables are also known to make people bored and demotivated.
If you are in a lower set and in a big school you are most likely being told you are being helped but still getting nowhere. This is done on purpose. Big schools usually dont want to look like a bad school where their students only acheive poor grades, so they will help the students who are getting better grades to give them a better chance of getting a high grade in their exam and will lie to the students who are not doing as well to make them feel like they are getting all the help but really are not getting enough help to do any better than a pass. The easiest way to tell if your school is doing this is to pay attention to the end of term assemblys, if the head teacher (or anyone else but its usually the head teacher) is always talking about how the school is "the best school in the area" or "the best school in the country" and just seems to be obsessed with the school and its performance.
UK schools require students to wear uniforms, usually the same uniform for every school with the blazer and colours being differant for each school. The problem is if you go to a school thats knows for having lots of bullies or violence or something else thats bad, your uniform tells everyone what school you go to, and when people see your uniform which is asociated with e.g. a school known for having loads of nasty students, then people are going to think your one of those nasty students even though you could be the nicest person in the school.
School uniforms also take away your freedom to look how you want, blazers can be heavy which is horrible on hot days, ties can strangle you, school shoes can become uncomfortable. There are more faults with school uniforms than there are good things.