Is it possible to get into a top 20 school without submitting any ACT/SAT scores?
Possible? Yes, BUT you still need to have the rest of your application be strong (grades, other test scores like SAT Subject Tests or AP if available, letters, essays etc.) so that Admissions Offices are certain that you can handle the coursework AND will take advantage of the resources at their college.
The Questbridge eligibility requirements sums it up in the same way:
“Students who do not have standardized test scores can still be selected as Finalists if the rest of their application is strong; however, they should ensure they meet the standardized testing requirements for each college partner they’re interested in.” So make sure to confirm with each college’s website/admissions office that they’re test-optional!
Link: https://www.questbridge.org/high-school-students/national-college-match/who-should-apply
Hope that helps! Good luck with admissions!
In addition, the app/supps need to reflect the perspective and personal assets/strengths these ‘most competitive’ colleges want. That’s much trickier. You have to understand what that is.
Don’t fool yourself that not submitting one data point (ACT/SAT or any AP) makes it easier.