For one, that extra education? It often isn't seen as part of one's career. But for any course worth its salt, those years are still draining. It's a minor point, but also an overlooked one.

Second, there's the mismatch problem. Outside STEM, loads of people aren't getting jobs in their fields. Inside STEM (mostly tech, really), most people are getting tech jobs completely different from what they learned in school. Often uninteresting and/or boggled with politics and bureaucracy (read: majority of them are CRUD webdev jobs trying to appease corporate's whims).

Third, the job market is ravenous. Absolutely ravenous. Anyone not solidly mid career is discriminated against to some degree. Too old? Have fun being seen as a liability despite your experience. Too young? Here's a set of requirements you wouldn't learn in most corporations, schools won't teach you and somehow you're magically supposed to get this experienced in a corporate setting, noted as "requirements". Oh, and you better cite the company's values by heart and claim it's your dream job, even if their product is yet another luxury / minimal improvement driven to make profits, as there are 20 others lined up.

The whole burnout thing already starts before you enter your first job.

True that K-12 costs more, but public assistance in higher education is substantial [1]. From grants, subsidized loans to directed money into public universities, it's a sizable investment at the state and federal level. It'd be more efficient to take that money and invest it directly in vocational schools if we knew people would utilize it and then swap careers due to burn out.

1 - https://www.pewtrusts.org/en/research-and-analysis/issue-bri...

Edit: Updated reference to 2019 version.

Most people joining the tech industry today aren't doing it because they're particularly good at it, or they want to. It's the best way to raise capital to do something else.