Why is the GSCE system so unfair and how it is disruptive towards teenagers

I have experienced the GSCE system and I have seen how it has disrupted so many peoples mental healths. Of course, exams are important. Exams were created hundreds of years ago to be more fair towards all students, to create a test. There is nothing wrong with having exams, but my main issue is HOW these exams work.

For example, the grade boundaries. Why should our results be based on how the entire country performs? How is that fair? If I sat an exam in 2018 I could've gotten a 7 but if I sat the exam in 2019 I would've gotten a 5. I do not understand how this is fair at all and cannot be justified.

Furthermore, how course work isn't very popular in GSCES. Exams are good, but exams in this system is just to test your memory rather than your knowledge. Thats why course work is great, because it is evenly spread out throughout the two years of gsce and is less stressful and more fair.

Another point is how there are so many exam boards. I mean, it is good to have a variety but my complaint here is the questions and how they word them. You're telling me if I sat an AQA Maths paper I could have gotten an 8 just because there was content that was easier that year (for me as an individual) than if I sat an EDEXCEL paper and would have gotten a 6.

Also talking about private and state schools... I go to a private school and I am very grateful I go to one. But I find it unfair for state schools as many lack resources - which leads to my next point. How is it any fair to compare a private and a state school child (of course not all state schools lack resources but here I am talking about the ones that do.) if one has more education and support than the other? I am not talking about comparing a state school and a private school kid here, but more about how the system is unfair to compare the two.