High school is becoming more dumbed down so that people can pass state exams and graduate rather than teaching the knowledge that we used to consider foundational. We've lowered expectations and extended adolescence so much that we no longer expect 18 year olds to be mature and capable adults, which shouldn't be the case.
Your view of trade schools is severely skewed though, and is really indicative of the problem discussed in the article. Most trade schools do not turn you into a worker on a production line, they teach you to be a skilled worker or artisan in a trade. You don't go to a trade school to be an assembly line worker, those are jobs that are taught on the job and are typically low paying. You go to a trade school to be an electrician, mechanic, carpenter, welder, etc. These are skilled jobs that are difficult and challenging. They are also jobs that have a greatly accelerated pay scale, and often lead to jobs that pay as high or higher than the large majority of college degrees (maybe STEM excluded), particularly if you are able to start your own business in the trade.