Some of that is due to regulatory capture. A big role of government certifications and minimum requirements and private accreditations is to artificially limit supply. For example consider the ADA (a private “professional organization”) fighting the introduction of a lower cost role called “Dental Therapist” to perform the most common mechanical procedures cheaply: https://reason.com/2017/02/22/the-nonsensical-argument-again...

Another part of it is that American college education has low upfront costs typically, due to the high supply of government loans and grants. This lets students access college with low short term financial burden and removes the immediacy of considering the cost benefit tradeoff. This is why we have tens of thousands of students graduating every year with degrees in fields with no economic value. There isn’t a clear incentive and feedback signal to tell students “get a degree in what society values” instead of “get a degree in your area of interest”. And then later when they’re unemployable or paid less than they’d like, they act confused as if the system is broken even though it was their choice to not study something that others value enough to pay for. That shows up in various political struggles 10-20 years later, as large quantities of those very same students now feel left behind.

Germany is different not only because of the availability of diverse education paths (like vocational programs), but due to its culture. The trades are respected in Germany. In the US that cultural value on trades has diminished. And now we are seeing many of those trades compensated heavily due to reduced supply.