Geographic mobility in the USA has been declining for decades but it’s still probably the most mobile least rooted nation in the Western world. Whether you’re talking about immigrants from abroad or internal migration from the North to the Sunbelt and South or post WWII migration to California, the Great Migration of Southern Blacks to what’s now the Rustbelt or before that Appalachians and Okies to the West Americans are extremely mobile. Most people live near their family still but a culture where the professional classes move away from home for college and probably move again for their first job will have a lot of people living nowhere near any family. Even apart from the professional classes people from economically depressed classes join the military in droves and they move where they’re sent and often settle there after their enlistment.