How many nations fall into that category?

There are only roughly 28 nations on earth with a GDP per capita over $20,000 for example.

I happen to find what the six or so best managed welfare states in Europe have accomplished, to be impressive. However, for every Sweden in Europe, there are two Bulgarias. Or there's France, which has seen economic stagnation for nearly a generation. Most of the well-managed welfare states have seen zero or near-zero economic growth for nearly a decade at this point, while their debt has exploded vastly higher as they try to fake-maintain their present standard of living by stealing from the future.