Historically Americans have benefited from income asymmetry and a fairly wide-spread desire by foreign nations not to cause too much legal trouble for US nationals abroad.
I have quite a few friends that do live, quite happily, abroad. But the common pattern for them is a.) fluency in the native language b.) historical association with the country c.) fairly large cash reserves so they can ignore any economic problems these countries are facing.
What people often mean by a "true expat" is something completely different: someone sent abroad by their employer, usually with a generous expatriate package (home-country salary, local allowances, housing, private schooling for children, etc.)
More broadly, though, expatriate simply means someone living outside their native country. Ex means "out of", and patria means "native country" or "homeland". It's that simple.
So the word itself isn't limited to wealthy retirees or corporate transfers. All immigrants are expatriates, although not every expatriate is necessarily an immigrant.
EDIT: Don't get me wrong, my European nation did a lot of bad shit, but don't put the idea of an "expat" on us.
Pros: Great food, interesting cultural past, only one language to deal with and not complicated accents to grasp (more important that most people think), gorgeous wild areas, uncomplicated people, maybe a little on the introverted side at first, but solid gold after a while.
Cons: Risk of poverty sadly high, bigger than many US states (but with better government support and healthcare). Harsh continental climate very hot and very cold. Not for everybody (but US has plenty of places with similar or worse weather). The trains and communication roads are also under-average for the country and many people don't really speak English.
In many of the non highly touristic places you can live well if you can adapt to the cons. Housing prices are lower, life expenses cheaper and buying a house should be affordable with a decent job (Don't try this in Barcelona or Madrid). Portugal is close, and is even cheaper, to the point of some people living there and working in Spain. To support the same standard of living in Barcelona, Valencia or Madrid you need to plan in advance, to stomach the stress that unavoidably come with big cities, and earn much more.
In Spain if you can speak English well you will be automatically seen as a great researcher.
More cons: You will eventually have to shift to a very different customer service climate and hours. The development levels can vary quite a bit, especially "modern" infrastructure like internet outside of the major cities (maybe that's gotten better in the last 5 years). Bureaucracy of some institutions (government/finance) can be extremely frustrating.
Regarding bureaucracy I'm afraid that there has been no such progress. Extremely frustrating that even when I do everything right, I get told to come back another day for my trámite because they just...haven't done it! Sorry!
Some of my non-Spanish European colleagues also have commented that the education system is kind of "good not great" especially compared with other Western/Central European countries. However, I understand the Spanish system to be somewhat federated; perhaps the difference between Extremadura and Andalusia would explain the difference in opinion.
So doing better than that isn't too hard.
People also embed themselves in different communities when they move anywhere, even to a different city or state in the same country. It's a clean reset.
It doesn't always last forever. I know several people who tried to move somewhere, including internationally, when politics got heated in 2016. Most of them came back eventually with a realization that politics is everywhere, it's just a matter of how much you're embedded into the places it's discussed.
In that sense most EU countries are a positive upgrade.
