Earlier quoted context omitted.
At a suburban population density of 640/mi^2 (1 acre/person), a circle with 3 mile radius covers 18000 people. A 2 mile radius covers 8000. A 1.5 mile radius covers 4500. A 1 mile radius, only 2000. A 0.5 mile radius has 500 people in it. Realistically, a person walking at 3 mi/h won't walk more than 0.5 miles to visit the local shop, and a person bicycling at 12 mi/h won't go more than 3. They won't, unless they are…
Many places don't even have sidewalks. The USA would be a much nicer place if no new residential development could be built without sidewalks. It would only require a little vision on the part of planning & zoning boards, with perhaps a little empathy for children, the elderly, and others who can't drive.
Besides that, have you ever read a zoning law? Be careful what you wish for; you just might get it, good and hard.