The 60s-80s-born generation performed a real doozy and told their kids "you can be anything you wanted!", so of course we ended up with a culling in trades and "plebian" jobs, and an explosive influx into "soft skills" like history, literature, etc., since that's far better than milling drill-bits all day right?

The craziest thing is that this has been a totally first-world thing. Any english/american university student will tell you how engineering degree courses are made up predominately of foreign students, where-as the less employable and "trade"-producing courses are dominanted by the firsr-world population.

I did Physics. It was 130 students 120 white male, 9 white female, 1 black female. Zero international students

Same university, but mechanical engineering, 70%+ black, 70%+ international students (india/china essentially).

So, to answer your question to what happened to trade schools: they still exist, but the first world young white generation doesn't want to do it anymore, and foriegn/black students have filled in the gap, for whatever that may be.