I agree that AP exams are often too easy and do not require a good understanding of the material, but [...] is the only thing in your whole post that's really relevant to this.

I also wrote:

"On an object level, based on my experience taking the AP calculus exams as a high schooler, my experience teaching calculus for three years at University of Illinois, and my revisiting the exams, I think that students who score 90% on an AP calculus exam know the material very well, and that students who score 63% (the lowest percentage needed to get a 5) have only marginal knowledge of the material."