I’m not American but my understanding is that many of those “suburban” residential blocks have sidewalks and you can walk around withing the confinement of your block. However blocks are isolated from each other and you need a car to go somewhere else.
There are places in the US, that when you buy a house or property, you are given a choice. You can build a sidewalk for it yourself, or you can pay the city/county for a sidewalk.
The thing is, if you pay the city/county for the sidewalk, they stipulate that they can build that sidewalk where ever they want. This does not have to include in front of, or anywhere near, your house
The US is a very strange place.