The reason why student debt is basically unheard of in Denmark since college is free (although to make that happen, the Danish government poses high taxation towards citizens like they do in order to maintain stable social security nets like subsidised healthcare and public housing, also why they have less homelessness).
Mainly Danish, Swiss and European citizens are eligible to study without stressing over student debt upon graduation. It stems from this: Danish government is more on for the people while American government is more on caring about themselves plus nepotism on the side (MORE & HIGHER TAXES TOO ON TOP OF THAT).
Works in Germany as well (with a very low fee, nearly free).
We believe that education is a basic human right. The human rights are equal for all humans (listen, Usamericans: humans, not just “citizens”), therefore it must not happen that low income can hinder it. And that’s also the reason why German universities regularly accept a good number of students from all over the world.
Why it “works”? Well it’s simply the government’s job to make it work. We, the people pay them for doing their job. As you might know, or not, in a democracy the people are the highest authority.