This happens in America; the difference is that there is an expectation that parental means play a role in success (both in the way the system is oriented and on the part of parents themselves). Most, though not all, of the time, those with clear and high aptitude are "tracked" into gifted programs and magnet schools (though the efficacy varies based on local conditions, re: school funding models in the US). For those with moderate or middling aptitude, it's up to the parents to support and advocate for their child; there is an ostensible cut-off, but it's blurred by the degree of access to tutors or coaches and by the parents' savvy with navigating qualification procedures (often including places where subjectivity can sneak in, like interviews). This, of course, favors the children of wealthy and well-educated parents.

This runs through to post-secondary education. America's college admissions system is legendarily rife with corruption, even into its basic structure; you think it starts there?