I am from Brazil and highschool was hell because of college entrance exams. Everything we did was geared towards optimizing delivery time for exam knowledge/practice. We didn't even have PE after first year.

I was very lucky to be able to be engaged in that sort of environment, but at least 50% of my class was not.

It is unfortunate but it has a weird side-effect, the system really promotes ambitious people and endurance. Most of my "top-tier" uni class was middle class, the rich kids couldn't/wouldn't keep up. But that 50% of my high-school class really get the shaft in that system, but the ones that survived it were highly regarded in the job market by the degree alone.