> Obviously, once you have work experience and letters of reference, no one cares about your college. But you're not going to have that when you're 18.
That's actually not the case, unfortunately. My wife is fluent in two languages, can read and communicate in a couple more but isn't fluent, has 12+ years of experience, and letters of reference from CFOs and CEOs from major international corporations, and is struggling (here in the US) to get a non-minimum wage job in a medium sized city (we'd be better off if we were in a larger city, but this is where my work is right now).
My point was more that the signal an elite college serves is relatively short lived assuming you then get experience at highly regarded employers. For example, once you have worked at a FAANG, no one cares if you went to a low ranked school.
Obviously, once you have work experience and letters of reference, no one cares about your college. But you're not going to have that when you're 18.
University is also a social exercise, which can serve to signal that you are okay or at least exposed to the type of cultural norms that might exist at an employer that is already full of similarly college educated people.