A quarter mile of dodging cars with an ungainly, loaded shopping cart sure does sound like an "inconvenience," and not one I would recommend to a friend to improve their fitness.
But I stand by the statement that most able-bodied Americans could find some way to incorporate more human-powered transport into their routine if they really wanted to. And in many cases they could do it without any adding any superfluous travel. I.e., it may be slower or even less convenient in some way, but it was a trip you were going to make anyway. You're just changing the mode of transit.
(Incidentally if it's truly too dangerous or inconvenient to walk across the Costco parking lot with a loaded shopping cart I think we're well on our way to the people from Wall-E.)
You can't win debates with such people, about biking or walking; there's always another reason why they (and all other good and upstanding Americans) can't possibly walk or bike. When they run out of their own made up reasons, it's "well what about disabled people!"
Like yeah, they maybe can't, are you disabled? No? Well then.
Not sure if you or OP are in the US or not, but American cities have zoning laws and infrastructure that are designed entirely around the car. Aside from a few exceptions, towns in the US aren't like European towns in the slightest. It really is often the case that nothing is walkable or bikeable. The "Not Just Bikes" YouTube channel goes into all this if you are interested in that sort of stuff.
But I stand by the statement that most able-bodied Americans could find some way to incorporate more human-powered transport into their routine if they really wanted to. And in many cases they could do it without any adding any superfluous travel. I.e., it may be slower or even less convenient in some way, but it was a trip you were going to make anyway. You're just changing the mode of transit.
(Incidentally if it's truly too dangerous or inconvenient to walk across the Costco parking lot with a loaded shopping cart I think we're well on our way to the people from Wall-E.)