.....the physical plant of “a college” is basically identical to that of any high school.....
NOT TRUE!!!! There are all those laboratories, plus student housing, dining facilities, and much more!!!! Take a good look at any university website—the physical plants of universities are much more elaborate than those of high schools or even most community colleges.
Yes, federal and other grants pay for laboratories and research, but there is all that overhead and administrative cost to run them.
IMHO, the REAL problem is all that overhead for “administration”, which has increased at a galloping rate over the past several decades!! That’s also where most of the wokeness comes in—i..e, the hiring of “deans of diversity”, etc.
Administrative wokeness usually dwarfs faculty wokeness! It also mandates much of the faculty wokeness, e.g., by requiring “diverse” faculty hiring.
A woke administration and faculty is also expensive, and contributes a lot to all that student debt!!
Plus it cost a heck of a lot to keep those campuses all perfectly groomed with the park like environment.