Accredited institutions can issue degrees if you pass their courses. There are various "grades" that bucket people, but as far as getting the degree goes, you just need to pass. Grading is at least ostensibly objective. Admissions to accredited institutions is selective, and colleges compete with one another for students.
The only two differences are price per class and "objective grading".
The former amounts to "what if we had our current system, except everything were cheaper". Which, I guess I have to admit, would indeed be nice. It'd be nice if healthcare and cars and real estate were cheaper as well. Not sure how to actually do it, though.
And for the latter, we've done that in K12 (standardized tests). Almost everyone seems to agree it's a terrible system.