I have a sibling who moved to Austria in 2008. He's never coming back. He doesn't notice a significant difference in his tax rate from when he lived in the U.S. (Oregon and Washington, mostly). He does notice he has much better health care at a much lower cost. He lives in a beautiful place, in a clean city, with a good job in a nearby city that he commutes to on quality public transit. His step-children had good access to affordable higher education. He gets a lot of vacation every year. Austria isn't perfect, but it's pretty darned nice. It also depends on NATO (read, at least historically: the U.S.) for its national defense. It is also much smaller than the U.S., has a more homogenous population, and largely depends on its neighbors for generating its economy. The country's government has taken a hard-right turn as a result of immigration, largely driven by the Arab Spring and the Syrian civil war. Austria probably, mostly, has U.S. interventionism in Iraq to thank for that. But maybe not.
He keeps his U.S. citizenship. I'm not sure if he's yet gotten his Austrian citizenship. He can have both, I think, but--at least a decade ago--he was hesitant to call himself anything other than an American.
I have a work colleague who lives most of the year (10+months?) in Barcelona. It was intended to be a one-year thing, but she's been there since 2019. Don't know if she's really coming back, although she keeps her house here, too. Her daughter has been going to school in Barcelona, so it will be a thing to pull her out and bring her back here.
I think I would enjoy living in Europe for a year or so, but I'm an American, and it will always be my home. I think the U.S. is a special place, driven by its political formation, its geography, size, location, and population. But it isn't the only good place to live in the world.
That said, it takes a decent amount of money to move to Europe, Australia, New Zealand, etc. Just as it takes some money to move from California to Texas, or Mississippi to New York. For a lot of people, "if you don't love it, leave it" isn't realistic.
