The problem is that to go from not needing a car every day to not needing a car at all is a huge leap that has a lot less to do with the geography of daily task

The problem is that to go from not needing a car every day to not needing a car at all is a huge leap that has a lot less to do with the geography of daily tasks and more to do with the geography of everywhere you'll go, as well as things like crime and pleasantness of local spaces, etc. That's why 85% of German households own a car, even though many of their cities are more walkable. Being more walkable doesn't get you to being car free, it gets you to fewer miles driven. But if your goal is to be car free then you need to focus on a lot more than getting groceries. But as long as a large majority have cars, you are going to have a car focused city, which is exactly what most European cities are once you get out of the touristy downtown areas. So at best the walkability metric will give you a small downtown area that is not car-focused. That downtown area will be populated primarily by tourists, and most locals will live outside it, in a more car accessible part of the city.