You are right, middle class and up = pay for college. You will hear a sweet story now and then about a grant, but 99 out of a 100 times that is not offered to a student. You can fill out the forms and see what they offer, but don’t count on anything. The “meets 100% of financial need” means that the student and the parents can take out big loans to pay the school. Loans are considered financial aid to colleges and particularly USC.
I just advise, being aware, that financial aid, like merit aid, is grossly over stated and over marketed to get you emotionally invested in the school. Then mom and dad start taking the loans to do whatever they can for their kids. Thus the loan crisis and student debt. Just keep a cool head as you go through the process. Also beware of continuing student scholarships stories “you can get other scholarships as a sophomore” - there may be some students can apply to (a process), but most of those are for a couple thousand here or there. Even if you hear about one for 10k, know there aren’t many (if any that year) and they are just as competitive (if not more so) than recent merit awards, plus that still doesn’t make a big ding on a school that costs 70K a year. The fact you started this thread shows you are aware and responsible - good for you!