For a long time now, a high GPA hasn’t been enough on its own to gain admission to top colleges. It used to be that each school had its own entrance exam, until standardized testing came into play in the early 20th century. The SAT and ACT have been a non-negotiable part of getting into college for decades now, and only recently has that changed with record numbers of schools going test-optional. Even in those cases, applicants are usually expected to write a strong essay or have outstanding extracurriculars.
All this is to say: straight As are great, but they’re just not enough for most colleges to let you in.
That might seem overly picky, but there’s a good reason for it. Despite educators’ best efforts, schools across the U.S. aren’t standardized. Sure, they all have to meet certain standards of education, but there can be a lot of variation in the quality of instruction between schools–or even between classes at the same school. Two kids can have a 4.0 GPA, but while one took all the toughest AP courses they could handle, the other took it easy with basic courses and electives. Or maybe one went to a rigorous private high school with some of the best teachers in the country, and the other went to an underserved public school with much fewer resources for students. They made the same grades on paper, but one is much more ready for college than the other.
This isn’t to say that grades aren’t important, because they definitely are! But, they’re just not a very fair way to assess the mountains of college applicants that popular schools deal with. By contrast, standardized testing is the fairest way we’ve figured out so far.