Where I lived in Italy, there were several single family homes near where we lived, which was in a 6-unit building. No one prevents it; it's just a market thin

Where I lived in Italy, there were several single family homes near where we lived, which was in a 6-unit building. No one prevents it; it's just a market thing. Want to live in SF or NY? Maybe you should be ok with some density. Not wanting that is fine too - live somewhere else with more room.