We’ve never had as many working age people as we do today
In absolute numbers that is true, but the workforce has declined relative to the size of the population. If there are two people and one of them is in the workforce, that might be okay. If the population then grows to 100 people and now two people are in the workforce, you've doubled the workforce!, but you're bound to have a bad time.
The questions are “why can’t we attract workers into X fields”
Because the workforce has shrunk, relative to the need for workers. A larger population needs more productive capacity.
but more national, question of “why does a worker, that produces more than ever, have less purchasing power than ever?”
Because we reached peak worker productivity a long, long time ago. Overall productivity is up only because capital has picked up the slack.
Funny thing is, once upon a time we encouraged our youth into university research labs to develop new capital which they could capitalize on, promising a higher income on the back of the productivity of the capital. Curiously, we heard the university part, and we heard the higher income part, but glazed over the rest. For some reason that message turned into people thinking they should go to university to get a job where they can be no more productive than any other person has ever been. And, unsurprisingly, incomes have held stagnant for that segment of the population, to which they now act like we have no idea what's going on...