“There is no reason why a student with access to a four-year university shouldn’t graduate with about 60 hours of AP and dual enrollment credit, thus saving a full two years of college expense.”
A few reasons, some kids have ECs, for example competitive sports or part-time jobs as well as a full class schedule so they can’t take dual enrollment at a four year college. Also, for some schools, you don’t get college credit for some AP classes. Lastly, many kids want to attend college for 4 years to get the full college experience and figure out what they want to do for the rest of their life. It’s just isn’t about how much money they can save by taking DE and APs in high school.