So, the comment I've got from engineering companies is; 1) the old experienced guys are old, and retiring, and want $,$$$; 2) they don't really want to sink the time/expense into a fresh EIT (Engineer In Training; ie, fresh out of college; who no offense, are worthless for atleast the first 6 months at a minimum), and then once they have their PE, they move on. What I've been told is what they all really need are journey type guys.
Construction; and I'll admit I'm part od the problem; you are literally missing an entire generation. Lots of guys in their 60s; and quite a few in there 20s; but all of us that where in it in '08, got the heck out, and didn't come back. So, as the old farts die off, they don't have experienced people in the field. I'm still 'construction adjacent', and around it every day, but not really part of the active process. Look at superintendents (BTW, commercial or multi family supers are often making over $100k if they are willing to travel), you've got guys in their 60s (the experienced ones from '08 that survived), and guys that might be pushing 30, that got into it in '14/15/16.
I'm sure other professions have a similar issue; but I doubt many lost any entire generation of people.
Trucking is gonna get rough in 5 or 10 years; with the new CDL requirements; and smaller outfits not being able to put a new hire through 6 week driving school. Many lease truck dump truck and local haulers had in the past official or unofficially partnered with jails/prisons and could put new release in a truck with a trainer for 1 week, and then make money off him. If your running say 5 or 10 trucks, your not going to pay the $6k to get a new driver licensed, only for him or her to leave in 3 months.
Very small sample, but nurses, seem to be very old; in late 30s early 40s, but only 5 years experience, or 21.