and UK has the most rigorous Anglosphere education system, where they just care about A level exam results. A levels aren't as hard as gaokao, but are pretty rigorous in their own right. For example, A level foreign language Chinese is
harder than HSK 6/6.
US has no entrance exam, but instead replaces it by considering the
very, very important parameters of... affirmative action (race), legacy (whether your parents are alumni), sports ability (even for academic subjects), etc.
, even the piss easy (compared to gaokao and A levels) SAT, and
So if even the most rigorous Anglo education system has problems...