I'm glad to now live in a human-scale city in Eastern Europe. There are three "western style" grocery stores with a 5 min walk and (not including all the low-cost high-quality locally-grown fruit and vegetable kiosks). It's a bit difficult to convey how much better (or natural, rather) this way of living is to my suburb friends and family back home without experiencing it first hand.
I get that, if you have a car it probably doesn't bother you, but the amount of logistics to have your children and maybe elderly no longer able to drive shipped around for everything must be enormous? I don't have kids but just from remembering what me and my siblings did on ourselves (from getting hair cut to going to sport clubs) from kindergarten age onwards, by walking and later cycling. I'd have to hire a driver. I only remember ever been in the car as a kid when going to another city or weekend trips.
Just reading this makes me feel kind of claustrophobic.
In terms of walking for leisure and exercise, some do, but not everyone. I see people walking/jogging/biking through the neighborhood throughout the day. But the rate at which people do is likely lower than those living in more urban areas. As mentioned by commenters above, just about the only reason to walk outside in the suburbs is leisure/exercise. The nearest non-residential area from me is about 1 mile away, and that's the city core, with some restaurants, dental offices, etc. The closest grocery is probably another half mile. And I'm far closer than most. I'd say the average distance to a non-residential area for most of the city's residents is closer to 2 miles, and the average distance to a grocery store is probably near 3.
But even strictly for leisure, there are likely fewer people walking here than other cities/countries. When I lived in Japan, I went walking because if you go outside, you are basically in the street. It incentivizes walking somewhere like a park, or a shop, or path, or somewhere interesting. In a neighborhood like mine, most people have large enough yards where they can easily relax there. You can throw a football or kick a soccer ball easily. Houses with kids will often have swing sets or trampolines in their backyards. I'm in Indiana, so I estimate no less than 40% of households have a basketball hoop in their driveway or on the street in front of their house. A lot of the things that drive you to walk places in denser cities simply don't exist. Walking outside becomes a decision to walk for the sake of walking, because most people already what they would be going to a park for at home (greenery, space, playground/sporting equipment, even pools are common), and you aren't going to be close enough to actually walk to many destinations.
It's popular to imply Americans don't walk. It's true the culture is more pragmatic (why walk when I could drive and get more done), but it's not true that it's unusual to see people out walking on sidewalks, parks, and lakes.
My neighborhood has a walking trail around a small lake (takes 45 minutes to do a lap). There are 20-50 people walking it at almost anytime of day.
Often the businesses get crammed together on some busy streets with fast-moving traffic, large parking lots, and few sidewalks.
Not a good idea, but still normal in many suburbs.
The idea of walking anywhere is insane. To get from a typical suburb to the nearest business district or strip mall would usually require walking several miles along the shoulder, with frequent illegal crossing of arterial roads.
And of course in other places in the world where cities are old and streets are too small for sidewalks. Back streets in such places are comparable to alleys in the US.
I would have walked if there were any affordances at all, but ended up driving more often than not.
The Northeast has a lot of old places that you will see small strips of sidewalk and then no sidewalk, and then sidewalk again. Because they force the new construction to have it, but the stuff that was already there won't.
An American suburb is, basically by definition, never more than 15 minutes drive from a grocery store, a doctors office, a dental office, some sort of clothing store, at least one bar, at least one restaurant (usually 2+), at least one hair dresser, etc. It will usually all be ugly (strip malls are common), but it will be affordable and economically sustainable. You can walk or bike anywhere (sidewalks are usually nicer than in the UK), but usually only car-based public transit is actually convenient (mainly because suburbs prioritize saving cash, and car-based public transit is always the cheapest transit).
If you truly need to drive 40+ minutes to get to a grocery store, you don't live in a suburb. You are either in an exurb, or just plain rural area.
which to a lot of the rest of the world is a really, really long ways and essentially "not in the same area".
Think beyond suburbia, which is really quite small in the scheme of things.
In some places you'll have continuous miles of nothing but housing. In others it's an organic "spread out and up" from a core area. It basically comes down to what the local economy can support and the level of development that happened between 1865 and 1945.
Having hard cutoffs from "most residences are apartments/duplexes/multi-family, businesses on every corner" to "residences and residences only, 99% single family" to "tractors commonly seen on the road" is pretty distinct to the areas surrounding major cities that were formerly sparsely populated until they were built out rapidly in the 1950s through 1970s.