Yes but there's plenty of institutions that all do what MIT does and field dependent probably better. It's simply not the case that MIT always represents the best all the time. It doesn't even make sense that that could be true. And why would you want it to be unless you were the MIT marketing department?

That assumes the fourish years of being surrounded by other students and professors who are smarter than you, and work harden than you, along with making friends with them does nothing for the students after their time there. Students entering MIT are used to being the smartest at their highschool and coasting through it. So it's a shock when those things are no longer true. (tbc, the same thing happens at other schools to a lesser degree.

First, a university is great by doing great stuff and producing great graduates. Then those great graduates confirm the greatness of the university. And then, ultimately, graduates are great simply by coming from an university that once did great things.