Earlier quoted context omitted.
As a mountaineer, you no doubt have a wonderfully ergonomic high volume backpack that is great for a week of shopping. Two if your diet is basic meat and veg not processed food in lots of packaging. Same to the OP. You should own a decent feckin' shopping bag. It's basic adulting where I live. You have observed the problem yet not doing anything about which is just really weird.
>You have observed the problem yet not doing anything about which is just really weird. They observed the problem and simply have a different solution than you. I'm sure there's a number of other factors they didn't mention that make it preferable to simply use their perfectly working car.
I'm sorry but when one is willing to put that much effort to try to justify using a car to avoid a 10 mn walk, that's only because one is way too lazy and privileged...