All currency issuers can always pay any debt denominated in their native currency.
Whether higher education is producing a quality product at a fair price is a completely different discussion.
Whether the degrees being produced align with the workforce needs is yet another different discussion.
Whether jobs actually require the degrees that employers specify is yet another different discussion.
And that decision is made when they are legally children, and they're bound to it for the rest of their lives.
Hell, most Uni students are 18, which means they're a legal adult. Most of them have been driving cars and fucking for years before then -- why wouldn't they be able to make choices about a career?
There is a reason why debt in nations is always mentioned as a percentage and not a raw number - the raw number is meaningless.
I also like to think back to what Peter Thiel says about higher education. It could be something similar to the 2008 housing crisis....where people were borrowing money to buy overvalued housing. Higher education to a certain extent could be people are borrowing large sums of money to get degrees that don't hold much value in the market place....so it becomes impossible for these people to ever repay the loans....overvalued assets and leverage spells bubble. I know people who borrowed 100k+ to get a degree in sociology only to realize after the fact that sociology is a worthless major. They then went back to spend another 100k to get a degree in nursing to finally become gainfully employed.
https://www.youtube.com/watch?v=crAHDXdBCXg