"What are the incentives to advance amd become highly skilled? Take doctors. Some are really passionate about what they do. Most may be a little passionate, but are mainly just intelligent people drawn by the money and prestige. Assuming medical school and university still exists, for what purpose would someone go through that pipeline when they could do something far easier?"

This is the argument I usually don't understand. Sure, it's hard. But well working in heavy industry is hard. Working customer service is damn hard. I'd be happy to read a lot of books and sew someone's wound up and get fed for it.

Maybe a better argument is why doctors and nurses get paid so differently. You probably need more nurses than doctors for a medical procedure. But the supply of doctors is lower. It's not that being a nurse is easier. It'd that the people who become nurses often don't qualify as doctors.

For me, things I'd qualify for might be writing, cooking, drawing, and programming. One of these pays far more than the others. Cooking professionally is probably a lot harder and yet more fun, but the economics don't add up. I can serve maybe 100 people a day at a restaurant, but I can serve millions/day writing code.

I think there's a kind of moralism here where people want to think they're richer because they had to sacrifice more. But often it's because they lucked into a well paid skillset.