If businesses were having problems hiring people in these fields, you'd think that they'd be a) offering higher pay and better benefits to make themselves more attractive to workers, and b) scrupulously avoiding filtering out qualified candidates for no good reason. Yet we don't see them doing either one. Tells me they want to use "shortage" as an excuse to move work overseas or bring in cheap labor from elsewhere.
We pay nurses, doctors, pharmacists, teachers and such crap wages, overwork them, force them to deal with idiotic gig-app scheduling, is it any wonder nobody wants to go into those fields? You have ICE showing up at construction sites arresting or scaring off half or more of the crew, pay them crap wages, and wonder why you can't get construction laborers? You outsource aircraft maintenance to the cheapest firm around and wonder why nobody wants to be an aircraft mechanic? Pull the other one, it's got bells on.