The most common case is that I'm picking up about three days' worth of ingredients at a time, in which case I walk either five or eight minutes (depending on which shop has the better stuff for my list) and carry home one large grocery bag. Since I don't need to worry about parking or traffic, I can fit this into my schedule whenever and usually do so when I'm already on my way home from somewhere else.
The actual minority case is that I'm picking up something in bulk (replacing pantry stock, getting supplies for a party, etc), in which case I might switch to using my car, depending on how heavy or unwieldy it is for a half-mile walk.
Three days of ingredients is a lot, with your toilet paper and laundry detergent and everything, this breaks down immediately if you're only two people. So if you are a couple then both of you have to go shopping, that's twice the time you spend. Not to mention if you are a family
Three days of food ingredients for two people isn't actually a lot, assuming you already have bulk staples (flour, sugar, rice, etc) in your pantry. I'm already including all the other incidentals outside of bulk staples: add occasional toilet paper rolls, paper towels, olive oil and vinegar, minor snacks, etc, and you get the one large grocery bag on average per trip. Maybe two if you're eating things that are bulky to carry (e.g. kale or something with a ton of eggs).
Like, come on. No typical two-person household is going through a full package of toilet paper and an entire mid-sized bottle of laundry detergent every three days.
The actual minority case is that I'm picking up something in bulk (replacing pantry stock, getting supplies for a party, etc), in which case I might switch to using my car, depending on how heavy or unwieldy it is for a half-mile walk.