I suspect these schools are riding on the coattails of great intellectuals from long ago, rather than anything recent.
Is there any quantitative evidence supporting your argument from the last 10 years?
Is there any quantitative evidence supporting your argument from the last 10 years?
Go study CS for a semester at one of those places.
What evidence are you looking for? How would you even quantify “great”? Just go there and see for yourself and go somewhere else.
I think the same is true for 1-20 vs 21-40, but it wouldn't be quite as clear-cut.
Top universities being top is not some kind of mass hysteria.