Its being accessible is the issue, that is, we don't want to miss a bright child of not so well-off parents who can't afford to pay a lot. Hence education credits: if you're bright and determined, a good education will give you a lot, and land you in a financially more gainful place.
OTOH a diploma becomes a token of costly signaling, "all good kids get a degree", so a lot of people go to college just for lulz, or to appease parents, which is a pretty bad use of their time, and also a source of crippling debt.
Here's where differentiation actually occurs: it's between the determined kids who actively work on and benefit from education, and unmotivated kids who just fool around, because peer pressure, parents, or fashion pushed them to a college which they don't care much about, or which teaches only unmarketable skills. It's a pretty painful and costly way to differentiate; I hope the society will eventually find a different way to achieve a similar effect.
(To say nothing of the rising cost of education, fueled by the unending source of the educational credit money.)
For the record: I did not press my son to go to college, and he decided not to go. I'm fine with it. He's got an engineering job anyway.
Perhaps on a purely relative scale, not much would change comparatively between the citizens. But the country's wealth will have increased.
Good plumber can advance standards of living and overall wealth much more than another failed literature critic. Who feels too smart to go to vocational school to learn plumbing after spending 4 years for useless diploma.
In my country, vast majority of people go to post-high-school education. The result is that a lot of people have bachelor's or even master's yet end up working shitty dead-end jobs. Which they could do as well right after high school. In fact, many places prefer to hire people without degrees for such jobs for various reasons. Effectively higher education becomes net negative if you went there for the lulz and didn't make it.