> employers across the economy who require applicants have 'university degrees'

Somebody from HR admitted to me that they often do it to simply trim the applicant pool to a more manageable size.

This is true across literally millions of HR people across the whole country. Every one trying to make their job a little bit easier and thus creating an externality with the monstrous negative effect on the entire education system and years of people lives pursuing pointless degrees at great cost and debt that may take some lifetimes to pay off. Absolute madness.

This is definitely part of it, but after working - and hiring - in the software industry for several decades I can say that a university grad has probably at least heard of relational algebra or taken a course that covered costing algorithms. Do they use this every day or ever? Definitely not, but when I interview non-uni grads the odds they can write (let alone explain) a modest SQL query are lower. There's very little causation between uni grad and good developer, but IME the best uni grads are better than the best non-uni grads. There's some signal in there.

Wonder if this problem would be reduced by some mechanism of incurring cost on job positions that advertise for more requirements. (A heavy handed approach would be to charge an additional fee/tax if you require university educated persons for a position not requiring one)