Was watching a video on suburban and the sameyness of it. I actually don't think much will change regarding building out. The point, I believe, was to get away from city crime. Therefore if there were more public transit, parks, walk and bike ways, it kind of goes against that because it's bringing it to them sort of. So maybe it's more than just single home zoning laws but what residents want.
By "building out", do you mean moving out from a city to the surrounding areas? In urban planning, that's called 'decentralization' and it's one of the only alternatives to over-crowded cities if they can't or won't build taller- it's also a place where people who can afford it build to 'get away' and many of them were wealthy.
The area where I grew up was originally part of the city of Milwaukee, but it was called 'North Milwaukee' when it became what it's called now, but they opted to form the local government as a village before eventually becoming a city. My parents decided to build there because of the high taxes in MKE, but also because people weren't packed in so tightly, better general conditions and it's still a quiet place. I moved back to the area when my parents started to have medical issues and it was a lot easier to be where I was needed when the wheels were falling off, but the vast majority of the noise we hear is from MKE, whether the noisemakers are stationary or when someone is fleeing from the Police and driving like a moron. I'm less than a mile from the PD and a fire station, so we hear sirens for fire/EMS calls, but we're accustomed to that. Hearing gunfire from MKE is never acceptable, but it happens frequently.
Farther out from the first ring outside of the city is where people want a more 'country-like' lifestyle and in many cases, larger land parcels are available. I have a friend whose place is larger, on an acre and his property tax bill is about 60% of mine. The sales tax is 2.5% lower too, because he's not in MKE county or city.