MIT does not require but not recommends the essay. MIT feels that they would already have an idea on your writing and communication skills through your essays and other application aspects than the SAT or ACT Essay. Also, AP classes are not proportional to academic excellence, especially since APs are an “American thing”. MIT wants to see you articulate your opportunities and balance your schedule to express given resources. IB, AICE, Duel Enrollment… whatever you have available to you. Some schools, especially private schools, have Honors or post-AP classes that are even more rigorous than AP courses such as Organic Chemistry, Multivariable Calculus, and Relativity Physics.
During my interview, I told my interviewer that I was the only student in my AP Physics C class because I was really interested in Physics but had no online alternative so I made an agreement with a teacher at my school to privately teach and grade me for credit. He asked me how many students were in my AP Calculus BC class, and I replied with “3”. He must have known that my school is not well know for prestigious STEM students, and that I was taking any opportunity I had to follow my passion in mathematics and Physics. In some schools, it is normal to take AP Physics C and AP Calculus BC. But for schools like mine, we are lucky to even have a class. This is why MIT doesn’t care about how many APs you take as much as how many you COULD take. One more note is that, by taking a lot of APs in one year, colleges such as MIT can view you as an AP-holic who would rather succumb to coursework and exams than to extracurricular and service activities. A balanced schedule between courses, extracurricular activities, research, and anything else is much better to both you and MIT than overloading yourself.