But that’s not how cities in Europe are laid out. The closest grocery store to me is 3 minutes by bike (1.19 km) and I live at the edge of my particular neighborhood (shops are usually concentrated near the center of neighborhoods). Even the city center (where the more specialized shops are) is only about 8 minutes by bike (or about 15 by car due to traffic).
Especially within the city a bike is always faster.
Have you visited a place where there were multiple stores within a 10 minute walk? Once I started living in places like that, my way of life changed in ways I never would have predicted.
Walking home from work meant I walked right by a grocery store, and I could grab something quick. Would I always? Nope. Did I sometimes still do big grocery store trips? Sure. And would I sometimes even bring my car if I had a bunch of stuff? Yes, because I lived up a tall hill.
The reason I mention this is that your well-established may simply change in unexpected ways that you never would have imagined.
Then women started working more and more, and they had less time to shop for food, so the supermarkets happened here too - much later than in the US though, because of space and legal constraints. But there is still an attraction for the traditional way of life that keeps a significant amount of smaller and more central stores in business, keeping shopping more distributed: one day you buy fish, the next you buy meat, and everything fits in your bag.
It also means you get fresh products. I’d hate to have to eat week old bread.