The courses taken depend so much on each individual school/district and policies. For admission to MIT or an equally elite STEM school taking the most rigorous classes is needed but having a good foundation/knowledge base to be able to keep up with the college classes is also needed. AP classes are equivalent only to merely average-college classes, not to those of top tier (not just elite) colleges.
Students also do not need to take AP classes to take and even do well on the AP exams. It is not necessary to take all AP classes/exams available. Scheduling conflicts can preclude taking some. Weigh pros and cons in course selection- it was better for my son to take 4th year French (and meet his future school’s foreign language requirements totally) rather than an AP Language course as a junior. They had an Honors junior language arts class that fit. A kid I knew placed out of the US history or AP US history requirement (some did regular before AP, others only AP) because he got a 5 on that AP exam before he would have taken the course.
Your job in helping your child choose classes (notice that as the years go by the student takes charge of choices) that work to give the best available education for that child. If the child is meant to go to MITs/he will. Many will not- there is a surplus of students who can thrive at every elite school.