[TrackerFF]

Not American either, but in the US many schools use/used standardized admission tests (SAT/ACT) on top of things like HS GPA/grades.

There are many countries, especially in Europe, where entrance/admission tests are not a thing.

[schnitzelstoat]

Yeah, in England only certain universities like Oxford and certain subjects like Mathematics have separate entrance exams.

That said, the Sixth Form exams are mostly standardised with only a few different exam boards for the entire country, so the Sixth Form grades end up being something akin to standardised tests anyway.