The truth is that it’s mostly not about you, the applicant.
It’s about the 20xx class they’re trying to build.
They are trying to create a class that is interesting and, yes, diverse enough (but perhaps not in the sense that you think about diversity) that just being a member of this class becomes a learning experience for all its participants and enhances the overall learning experience that you will get at Harvard or Yale, or wherever you study.
When students of a certain identifiable group complain that admission seems to be directed against them, despite their exemplary grades, scores, etc., they do not recognize that the admission process is not fair to them as individuals. It’s about using their apps as a kind of stucco clay to create a balanced and interesting classroom full of geniuses, high school student council presidents, French horn players, poets, cartoonists, actors, athletes, political activists and all the other 18-year-olds that exist in the world, and who all meet the appropriate standards of academic excellence.
Sometimes this means that the person whose scores (GPA, SAT, AP) are better does not enroll because other candidates are apparently more likely to contribute to the life of the university.