One issue with the highly selective private universities: All of the students were relatively close to being at the top of their class in high school. They are not all going to be in the top 1/2 of the class at MIT or Harvard or any other highly selective university. Someone has to be in the bottom 10% of the class at any of these schools. Different students will have different reactions to the sudden increase in rigor. Many will like it but many will find it stressful.
I think that today with the Internet students may be more likely to know what they are getting themselves into. Hopefully this will mean that more students can find a good fit compared to way back when I was dealing with the uptick in rigor between high school versus MIT.
Then there are students who don’t qualify for need based aid but do qualify for merit aid (which some top ranked schools don’t have).
Academically very strong students attend a very wide range of schools for a very wide range of reasons.