I grew up in Maryland, outside the DC area. I now live in Annapolis, Maryland, in a suburb. In between I lived in California cities, and later in California suburb an hour and a half outside SF. There are about a dozen kids at the bus stop nearby, including my two kids. When I lived in a California suburb it was similar.
In the city I never saw kids. When I did it wasn't a good experience and they didn't look happy. I never saw them without parents, and when I did I wondered where they were.
In the suburbs I see kids without their parents all the time. They are climbing in trees or riding on bikes. I drive my pickup truck within 30 minutes all the time, for everything from general shopping to also picking up various house related things (lumber, mulch, whatever).
I've lived in places where everything was walkable, and lived in SF for 5 years without a car. I didn't care for it, for the reasons I mentioned. I love going into cities for day trips, but I prefer living around families and yards.