system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is it common in the USA to buy houses even at a young age?

I'm german and I recognized that there seem to be lower barriers in the US to buy houses even at a young age. In Germany buying a house is rather considered as a "lifegoal", something you can think of after a long work life and/or when you have a well-paid job. Why is it more common in the US to buy houses instead of living in a flat/live in rented accomodation?

EDIT: Thanks for all the good and interesting answers so far!
gpt
The US has a lot more space relative to its population than Germany, so it's cheaper to buy land and residential neighborhoods tend to be more spread out and more likely to consist of separate houses. 

Another factor is that the layouts of major German cities tend to date back to way earlier than American cities; many American cities were built up after mass transit (trains, trolleys, cars, etc.) allowed residential neighborhoods to be spread out much more than the case in earlier years, when people had to walk everywhere. This allowed the US to take advantage of its landmass and build sprawling suburbs. It's difficult to make major changes to a city's basic layout once it's set in place because doing so would be extremely disruptive. You can see other differences between the US and Europe related to the age of cities as well, e.g. the widespread use of street grids in the US and the large number of cities in the Western US that could only be built after technology allowed massive quantities of water to be routed there.

Finally, there are historical factors related to race. White Americans fled the cities for the suburbs in large numbers in the middle of the last century to avoid integration. This process has reversed somewhat in recent years, but from the 1960s through the 1990s, urban areas were associated with ethnic minorities, crime, poverty, and decay while suburbs were associated with white affluence.