And you base that on...?
PL now spends about the least % of its GDP on healthcare out of the EU
You answered your own question. Also, I'm a pathologist, and I live here in Poland, and have for twelve years, so I think I know the lay of the land for the medical profession here a lot better than you do.
and that will only increase with the ageing population
There's very little money to be made in poor old people, especially if it's financed by a poor and stingy state. And the worst is still to happen as the baby-boomer generation starts to retire, leaving the much smaller baby-bust generations to foot the bill for their eldercare. This is a big problem even in rich Western countries. In Poland, it's going to be truly awful.
so certainly this is one profession that does not need to stress about their prospects...
That's wrong on so many levels that I don't even know where to start. The only bright star on the horizon for Polish health care workers is that they can always emigrate to Western countries, where the demand for their services is increasing.
quality of life/satisfaction - that I would say is really up to the individual to determine based on what their priorities are, especially if bringing up young children is involved
Poland scores far below the US on any objective indicator of life quality and satisfaction. You also seem to be conflating the US with New York City, and Poland with Europe, and romanticizing life in Poland. However, like Mexico, it's a good place to retire if you're single and living off of Western retirement funds, or if you can provide a unique service that is highly in demand (and someone is actually willing to pay for).
Having said that, though, I'll be returning to Chicago in two months because my Polish partner (an anesthesiologist) has had enough of Poland. Especially the poor wages and job prospects. The job lined up in Chicago pays ten times what the job in Poland did. Future savings potential is 25 times as much.