Exacerbated by the lack of sidewalks in many suburban neighborhoods. I once lived the equivalent of four city blocks from a grocery store but wouldn’t have been able to get there on foot without walking on the shoulder of a highway.
A lack of connectivity, too. Your parcel might be adjoining the back lot of the grocery store, but you cant get there without walking over a half mile to get out of your cul de sac and to the major road.
Where I live, that only exists on actual county highways or new suburbs. When they get to be 10-15 years old (and if it's grown enough to become a town or something), the local area typically makes an ordinance to have sidewalks.