I think much of the "useful" college experience can be shrunk to two years for most majors. May be not more specialized fields like aerospace, physics, or the like but even those can do just fine with a 3 yr undergraduate degree. But CS, finance, any arts/commerce majors, liberal arts should totally not need four long years.
Which is, almost ironically, going back to vocational training instead of standard Liberal Arts degrees. I triple-majored in Math, Physics, and Computer Science because I had to be there for the whole degree, so why not. But all I really needed, and all I use to this day, is the Computer Science portion.
We could probably eventually overhaul the system to that end, but I don't envy those trapped in the transition period.
