But none of my peers (that I know of) have an outstanding EC. So like what constitutes them being a better applicant? Is it simply because they have 2-4 more APs than me? Even if I manage to get all A's in my classes senior year, wouldn't that show that I'm more than capable of handling a rigorous curriculum?

Like I know a girl who's taking 6 APs this year. Like, what's the point....? There's no way the AO views taking as many APs as possible as being "more competitive" compared to the other applicant who takes A LOT of APs but not to the point of wanting to kill themselves. Because doesn't the holistic review count wayyy more once someone has met the minimum of a school's academic threshold?