That is my understanding also. Certainly I have known plenty of students who went to highly ranked universities from very ordinary suburban high schools. I have also known plenty of students who went to good but relatively “ordinary” undergraduate universities (let’s say 50 to 150 ranking) and then attended very good and very highly ranked graduate programs (eg, Ivy League or MIT or Stanford and/or “top 10” for the major).
I think that there may be valid reasons to attend a private high school, or even a prestigious boarding high school, but it is not obvious to me that getting into a good university is one of them.
Of course private high schools include things like Montessori and Waldorf schools, which may be focused more on having results similar to the competitive suburban public high schools but with less stress and more cooperation. This is of course somewhat different compared to a “prestigious” private boarding high school.
This is a valuable thing to learn. I think that we all need to learn it at some point.
This is bad enough at suburban public high schools.
OMG. This is sad.
It seems to me that life in general requires a lot of cooperation and a little bit of competition. Perhaps I would want my kids to attend schools that have the mix the right way here.
We had experience with some private schools, but they were all Montessori and/or Waldorf schools so limiting stress and encouraging cooperation was more the primary theme. Even here when one daughter decided to attend a small university in Canada that none of the other students had heard of she was bugged about it to some extent (this of course went away the moment that she arrived in Canada).
I can see how at a private boarding school there might be quite a bit of pressure to attend a highly ranked university, whether it makes sense or not in any particular case.
I think that one big reason that we did not consider a boarding high school was that we wanted to spend as much time with our kids as we could. When they were in elementary and middle school as one example each year I took 6 Monday afternoons off to ski with them and their school ski program. I still think that this is one of the best and most important things that I have ever done in my life.