You keep missing what I’m saying. Sure, the degree holders make much more, but the real question is,
why they make more.
Do they make more because they learned valuable skills allowing them to do valuable jobs that otherwise wouldn’t be done? Then yes, the government extracts part of the extra productivity they generate that wouldn’t have been generated but for the education.
Or maybe do they make more because the college degree certifies them as quality people, which signals their value as good workers, leading to employers choosing them over other people? In that case, college education doesn’t make the workers any more productive. No extra value is produced because of college education. However, the college educated workers in that world still make more than not educated workers. All college does then is to determine who gets to do the higher income jobs. If nobody went to college in that world, those exact same jobs would be done anyway, it’s just employers would have to use different signals for employee quality than college degree.
I believe that our world is much closer to the latter than to the former. College is mostly quality certification to signal value, and it’s not building human capital through teaching people skills that make them more productive. This is shown by papers like above, where they find that after controlling for other explanatory variables, college premium is zero or close to zero, but also by common sense: a typical college graduate forgets 95% of the material in class, and the remaining 5% is often not likely to be used anyway, since most degrees are not teaching any practical work skills anyway (except for the job of being a college professor), and on top of that a lot of people don’t even work in a job they have a degree for.