That's not true at all; only a small percent of any school's given student body actually gets scholarships and most don't qualify for grants. I do think international students are more likely to get scholarships for diversity and the whole "novelty" factor, like I know way to many people from Pakistan that got into Ive Leagues as opposed to Pakistani-Americans even if the latter are more qualified simply because getting an international student from Pakistan or another third world country has a "novelty" factor that a lot of colleges in America like + charging international tuition rates.
Vast majority of Americans don't get scholarships or grants unless they're like in the top percentile of their graduating class or have stellar test scores, extracurricular, and/or maybe excelled at a sport or musical instrument.