At highly selective colleges, they sort of do.
For first cut, they look for students who have shown they can do the work.
Then, they select the students who meet their institutional needs best.
They don’t have a fixed quota per school but they’ll never admit more than a certain number from one school and will try to balance out the different regions of the State and/or of the country.
Students are compared to all applicants from that one school since secondary schools offer such different curricula, but the criterion isn’t “who took the most AP’s”. The course selection and progression needs to “make sense” in relationship to purported interests but there’s no expectation a student will take every AP the school offers, unless the school only offers 4-6 with no access to dual enrollment classes.