This is in Phoenix, right? I haven't been there myself, but a friend was living there last year and he said that the city is 100 x 100 miles in size. Combined with the summer heat, I would probably get a car if I were living there, too. I do think certain US cities are good candidates for widespread bike commuting, but places like Phoenix will probably never be among them.
The valley area is quite sprawled out, but because in most areas everything you need is within a mile or few of your home, a bike is a very viable option, even a pedal bike, for most. Just not one they'd be willing to try.
I haven't checked, but I'd guess that at least a third, maybe half of people here work within that distance of their homes as well. There's plenty of cross-valley commuters who don't have that option for their job, though they often do have other transport options they generally are not willing to explore, either.
The "strip mall" phenomenon makes getting to whatever you need easy, as food, groceries, other goods, services, are usually in the closest one to your home, and if not they're probably in the next one.
There's exceptions; for instance I'd like to get a new tube for my right rear wheel and pick up a spare, but the closest place that carries such things for moped/motorcycle tires in the right size of a usable type that will sell to me (because I ride bicycles and not motorcycles or cars) is at least a dozen miles away. I'm waiting for the worst of the heat to pass before I go do that (it's already 116f and not even noon, today).
There's a great store that sells assorted grocery merchandise for very cheap; close-to-expiring lots, dented cans, restaurant-sized goods, etc., but it's across the valley, maybe 40-50 miles or so round trip? It's been a few years since I've gone there, so I don't remember exactly. I've made the trip a few ways, including by car with friends, and the only way that makes economic sense is by extreme cargo bike/trike with large trailer and filling it up till it will barely move.
But the reason I stopped going is that it's not a fun trip due to the route at that end of things: it's a canal path ride before that for much of it, and that's fun, or at least relaxing, but after that it's all busy city streets and detours around non-bike-passable areas. Just a regular bike would be usable in those areas, but wouldn't let me carry enough to be worth the trip, and the same is true of any trailer small enough to be usable in those areas. So I have to go around them, and that takes a lot of time (and battery range), adding a lot of hassle to the trip. It's too dangerous to ride straight there; the traffic is too fast and there's no protected provisions for even a regular bike much less something as huge as my bike-or-trike/trailer combo. Even though by being that large I *am* safer than a regular bike would be by dint of being more visible, it's still not enough, right there.
There's a number of places around the valley like that, not worth doing by bike for whatever reason, that a car might be. The grocery thing isn't, because it would cost enough in gas to negate savings enough that it'd be just about as good to simply hit all the good sales locally...which is what I do instead.