I was not a counselor, and because of that I am not going to try to guess why people do or do not get in. If they had unlimited space many more of you would get admitted because you will be a strong student in college, unfortunately they don’t have that and the cutoffs are not as black and white as some people make it seem.
Your SAT/ACT scores, GPA, AP/IB, extra curriculars and essays each individually do not determine whether you are in or not, it’s the whole package vs the 25,000 other packages that determine it. An extra 10 pints here or A there may have made a difference, but that is neither here nor there. With your stats you may have gotten in when I did, last year or next yesr, who knows. It’s just unfortunately this year they didn’t have space.
I wish I had a better answer but keep in mind that every that gets rejected would like to appeal, but they already reviewed your file. If something was wrong or something like that they will review. But otherwise they would have ankther review with no more space