I knew a classmate who openly admitted to putting made up volunteer activities on her college applications, arguing there was no chance the school would fact check her. She was right!
And (although we're revising the system and hopefully changing this part) the relative weighting of "significant achievements" of an easily fact-checked nature vs. "doing lots of stuff" has skewed heavily towards the latter; you could have a resume full of "volunteered at X" and "leader of student club Y" which would be worth as much as the difference between a 90% high school average and a 95% high school average, while containing nothing which would show up online or elicit commentary from a referee beyond "this student is heavily involved".
(We're putting together a new system starting next year which is aimed to be more about identifying students who are in some way exceptional as opposed to merely being generally all-round good people. A large part of the motivation for this is to avoid easily "gamed" metrics; nobody spends 15 years playing violin or becomes a national chess master simply because it will look good on their resume. So with luck we'll end up having less of a fact-checking problem in the future; but we're still going to have a significant amount of trust built into the system.)
If a school actually care about the diversity of its students, then judging on these activities self selects a much narrower socioeconomic background.
That demonstrates commitment in a way that volunteering for worthy causes never will.
(By the by, I'm a huge fan of your work. It inspired me to get into compression several years ago and it's been a passion project ever since.)
But the precise details of how this happens varies from person to person on the adjudication committee at my university, and I'd assume other institutions are similar. Some people opt for demographic indicators (e.g. "this is an indigenous student, and indigenous students tend to have less access to extracurricular activities"); I don't like that approach since I insist on evaluating individuals as individuals rather than as members of collectives. On the other hand, I'm probably unique in how much I look for a narrative and self-awareness; to me, what a student has done is less important than their ability to articulate why they did it (and so "working at McDonalds" by itself didn't count for much, but "working at McDonalds because ... [story about why higher education is important to the student and why they're willing to make sacrifices for it]" was crucial).
In some cases, I see students' extracurricular activities as demonstrating an ability to dedicate themselves to a cause or pursuit; that sort of perseverance is important in higher education. But in most cases that sort of dedication goes along with extraordinary success of the sorts you mention. (My personal scholarship assessment rubric actually includes a specific value for "competed in the Olympics or equivalent level of international competition".)
It turns out, a bunch of students got together, created a club, and each member was called a "President." The best part is that if an employer ever checked, any member could honestly say "yes, he's a President in that club."
I don't understand why is doing doing extracurricular in order to get to good university seen as "gaming". If anything, it is quite responsible behavior.
a system based on such bullshit is immoral.