The US is a big, big place. Between the coasts there's plenty of cheap space that to this day remains unused. People have become used to being able to buy large

The US is a big, big place. Between the coasts there's plenty of cheap space that to this day remains unused. People have become used to being able to buy larger and larger houses for decades. It's just American culture. I can't answer what people "do" with all the space... but friends of mine lived in houses like these and it's not like there was an unused room or ignore backyard. Everything was used.