I believe people in the US are more mobile, so you can end up living in area where you are 1000 kilometers away from your children or family.

In Europe, people are generally less mobile (geographically) and countries are smaller, so you can still work in the city and still live in the vicinity of your elderly parents (let's say one-two hour drive).

Maybe less obvious, but people in Europe also tend to have more vacation (understatement), so it is much easier to visit your family more frequently.

As a European I am always surprised that people only see their family during Thanksgiving. I don't have data but looking at people I know, you see your family much more frequently there.