The simple answer is that, after a certain number of APs, there is no benefit to more for the most elite colleges. I think that 8 is more than sufficient, and that assumes that your high school offers a large number.
My D was accepted to a top-5 college with 6 AP classes, plus two self-study tests. My S was accepted to many top-10 colleges with a plan of having 7 AP classes, plus two self-study tests. He finally ended up taking only 5 AP tests because in 2020 the college didn't care if the he took the tests his senior year.
Note that places like Georgia Tech, which is elite in engineering, seems to favor applicants with more APs. Other public schools may have a similar view.
