Could college be shortened to 3 years, and made less expensive that way?”
No, it could not be shortened and made less expensive. Probably would need to hire more profs to do the basic courses all at the same time, so you would have to raise registering fees. Also, more classrooms would be needed or construction of larger classrooms or same class rooms would be needed (bigger light bills…, ac/heating bills…) more during the week since those who already had taken those courses would need to take more advanced courses. Ditto for fact that as a prof only a certain number of monographs or tests or homework can be corrected/read/commented on per group before you would have to break up the group into three. Scheduling would demand more from staff… More library books to cover courses would be needed (for example, instead of 50 copies of some books, you would need 100). and so on and so on…