Not to say YC isn’t a big, impressive brand that draws talent, just that it’s still orders of magnitude from the top of the Ivy League.
It's just that people who attend college or are interested in college is a much bigger group than entrepreneur.
The concept of a university is fairly universal (pun intended) and surely Harvard or Oxford are considered the “best” at least in terms of name recognition.
https://en.m.wikipedia.org/wiki/List_of_universities_in_Yeme...
Harvard also isn't as well known as Coca Cola (not even remotely close in fact). That lower recognition doesn't mean that Harvard isn't a brand that represents eg a very high standard in its field.
https://www.forbes.com/sites/jacquelynsmith/2012/03/14/the-w...