I've been to Europe on vacation or for business about a dozen times in the last 30 years. I'm struck by how little it changes. It seems as if the whole place is stuck in the 1970s. Whereas California is radically different with huge amounts of building and migration. Even Boston (where I lived before coming to California) has visible signs of economic growth. But Europe has few such signs.
What's interesting about that to me, is that the numbers tell the same story. There has been significantly GDP per capita growth in Europe since the 1970s than here in the United States. And it shows.