I moved to Tokyo several years back and got married here, and have come to appreciate the effect of being in a city that isn’t a revolving door in a country where most people intend to live in the same city. My spouse’s friends all live here, so does her family across multiple generations, and the city is well connected so by default she has plenty of friends around all the time. Coming from a US flyover state where practically nobody who I know except for my parents still live there, it makes me not want to raise my future children in a place like that nor in a US big city where most people only intend to stay for several years max.