Very relatable! I think it's not so much money they're saving as time (or so they think). I have a friend who's getting packages delivered several times a week, then ends up sending a lot of it back, so more time wasted. It's a rabbit hole, this whole online shopping thing.
I think you're right about the supermarkets, although I gotta say, if I walked into one and they had delicious freshly baked goods on display right up front... well, I mean I would be giving them my business :))
Lovely post!