Generally, the definition of "best students" that the top universities are looking for is the ones who are best able to handle the content of the course by them

Generally, the definition of "best students" that the top universities are looking for is the ones who are best able to handle the content of the course by themselves without their parents there pushing them, because that's what it takes to succeed. They're not looking for the students who've most effectively been sheparded through intensive test prep by their parents, because that all falls apart the moment they have to stand on their own and deal with harder courses that can't be prepped for in the same way.