As in, the more people drive to a destination, the less pleasant and convenient it is to walk the same route, and the more attractive driving becomes.
I think, also, the more driving you do in general, the more it feels like the default.
Car oriented infrastructure makes cities less habitable.
But certainly point taken— that type of thing is well outside the norm. Most carfree urban dwellers I think handle this by just breaking up the shopping into more, smaller trips. Going every two days instead of every seven, and paying a slight premium for smaller packs of stuff like TP vs stockpiling 48 rolls at once.
And honestly, some of it is a mindset shift more than anything else. Like a lot of people who do these big whole-week mega shops still seem to be "popping out" to the store (in the car, of course) every other day anyway for some single item they forgot, emergency snacks, whatever. So maybe if you're there anyway, do the work and extend the meal plan another day or two, bring a backpack’s worth of stuff home, and avoid or defer the mega shop that justifies owning a car in the first place.
Or, as you say, having a car is just a given most places in America, so there’s not really a question of it being any other way.
I see the same with children. When I was young nobody wanted to be dropped off by their parents, everyone wanted to bike. I see it with my kids somewhat (they are still a bit young to bike to school alone here) and some colleagues kids (who are older) and it is an argument to bike to school. Interestingly this seems to be very school dependent some schools have almost all kids biking while others have none. It is almost like a phase transition.
Which is why it is important and justifiable to occasionally decide collectively to do things that may be perceived as “anti-car”, such as removing (or refusing to build) new car-serving infrastructure such as parking spaces.
America’s high parking requirements are one example for this. The parking lot is usually between a sidewalk (if it hasn’t gotten eaten to expand said parking lot) and the front entrance, reducing a given spot’s walkshed, and both being within a parking lot or crossing its driveways to pass one are not pleasant.