In the early 20th century having a high school degree was an accomplishment on par with having a bachelors degree now. And that lasted quite a while mainly due to factory work. I had a teacher in high school talk about when he started teaching in the 70s he had students who made more than him working part time in factories.

Of course the golden age of factory work has dried up but trade skills aren't in a position to dry up like that. Even with all the hype around machine learning and automation the skilled craftsman trades won't be automated away anytime soon, in fact software developers themselves are likely to be automated largely away before the trades. Along with other fields of IT.

Some might argue technology will replace some trades like plumbing that uses self healing polymers but someone still has to place the plumbing, someone still has to replace it when the damage is greater than the self healing capacity. The people replacing it won't be the engineers designing the polymers it will be the plumbers. If we ever increase space exploration and colonization guess what will be needed? Trade skills...