Why are some majors more stressful than others?

I can only speak to the schooling I’m currently getting as an undergraduate pursuing the premedical path. I think that while higher education is difficult, I wouldn’t call it a dystopia because there are quite a few people who like school or can balance it with a social life. It’s very difficult and I could understand how people would consider it a great suffering because it can be very time consuming. Personally, I don’t have much of a social life due to my course schedule and after hearing some of my friends talk about the workload of other majors it makes me think of how unfair it is that finishing all of your work/studying is never truly over for many students in STEM or who are pre-med. You are taught to be the student that stands out for applications by doing many extracurricular activities, but that doesn’t leave much time for anything other than being a stellar student.