This is not a contest to have the longest list of ECs. A student should not be doing ECs to impress admissions officers.
Instead, each student should do what is right for them, do it well, and treat people fairly. Be genuine while doing something constructive.
This is also my understanding of the recommendation of the “applying sideways” blog on the MIT admissions web site (a quick Google search will find it). However, everyone in my family took this approach before we saw the blog, and it did seem to work for us even though each of us did very different things.