For some reason, advice that students need to be "world-class" to get into top schools is all over the internet, reflected especially in the How to get into Harvard essay that shows up for every "How do I get into a top school" Google search. In high school, I read many responses like these and misunderstood the advice. I spent an insane amount of time practicing classical piano to win prestigious piano competitions to prove that I was world-class. Although being "world-class" at classical piano performance was a meaningful experience to me, it was not at all what actually helped me get into MIT, my alma mater, especially considering that I did not want to become a musician.
The misconception that you need to be "world-class" to get into a top school is just not true. Sure, if you get a gold medal in the IMO, you'll most likely get into MIT, but beating out everyone else in one of the most cutthroat competitions in the world is impossible for most students. The idea that you need to be "world-class" is really harmful for students because it puts pressure on them to achieve in the most obvious way to them, and not in a self-discovery, creative pursuits way, the kind that actually gets you into top schools and makes you successful in life.
A very successful friend of mine who recently sold his company once told me that the recipe for success is to "do something, reflect, then do something, and reflect again". When filling out college applications, what you're doing is writing a story about your life so far and connecting it to what you want to do in the future. You're telling a story about yourself through sharing details about your past experiences and relating how these experiences have influenced how you think and what you want to do.
In this context, doing extracurricular activities for the sake of going to a top school doesn't make sense because you can't share any unique thoughts about how these experiences have been interesting to you. Despite practicing piano every day for two hours for 12 years of my life, I couldn't verbalize why I was motivated to win piano competitions other than to achieve and feel successful. As a result, there was not a single essay in my college application that discussed winning piano competitions because I couldn't write anything compelling.
So what do you do instead? You should think about what you want to do, then do it, reflect, and repeat. Do it for fun, and to build your personal narrative: to better understand who you are as a person, and what you want to do with your life. Inherently, this means that many competitive activities students do for the resume point should immediately be ruled out as a waste of time.
Are you the Lieutenant Governor of Key Club because it looks good on your resume? If so, it's probably a waste of time because you won't be able to write a compelling narrative about it. On the other hand, if you love playing video games and reverse engineered games so that you can cheat on them, that's probably going to make a really compelling essay. Imagine if you had then further sold the cheat codes and made a large sum of money? And then the video game company hired you as a security freelancer? That would make a killer essay... and ironically, you probably didn't do any of it for college.
Equally ironically, no part of the video game example would be considered world-class because it has never been done before and it's not competitive. To take it a step further, the qualities that make the hacker in the video game example compelling to admissions officers are the qualities that make people successful at life in general. Everyone I've met at MIT is smart, good at taking tests, and can digest coursework quickly, but very few can think for themselves to produce truly creative work.
When I applied to MIT, instead of writing about how I spent the bulk of my time in high school practicing piano and taking AP classes for the "significant challenge" essay, I wrote about how a successful website that a couple friends and I built got DDoS-ed and discussed the steps I took to protect it. I had time to build this website because I took 3 free periods my senior year of high school to do whatever I want. If I could do high school over again, I would've spent the entirety of it doing what I had done in senior year: building cool stuff for fun.