I've witnessed this first hand via a friend of the family. Their kid didn't have the grades or entrance exam test scores to study what they wanted at university

I've witnessed this first hand via a friend of the family. Their kid didn't have the grades or entrance exam test scores to study what they wanted at university. So the kid got to take a year off after high school and focus entirely on studying for the entrance exams with regular tutoring from various private tutors. And while their test scores absolutely did improve quite a bit by doing this, they didn't improve enough, and they still ended up having to study at a secondary choice anyway.