First a disclaimer - I have not yet entered a traditional local grocery store, so what appears below is gleaned knowledge with little first-hand observation.
Houses in Belgium are small. Kitchens in Belgium are small. Refrigerators in small kitchens in small houses are small. As cold storage is limited, it is difficult to store more than a couple of day's worth of meals for a family. This means that food shopping must be done more than once a week.
For people who live in small towns, this may best be accomplished by visiting the local food markets. Most towns have a grocery store which is about the size of a small convenience store. Here one can buy dairy products, produce, and a limited amount of canned goods, meats, wines and the all important chocolate. Usually close by to the grocery store is a bakery - for the essential daily bread and also a local butcher.
If one does not live in the small town, shopping at such locations is not terribly convenient. These stores are typically located along a stretch of buildings that are hundreds of years old. The store building does not stand alone. It is one store front sandwiched between housing and/or other store fronts. It also doesn't sit that far off the street. Typically the distance from the store front to the front of the building across the street consists of - wide side walk, two lane road, wide side walk. If you are able to follow my description and visualize - you will quickly realize that there is no place to park one's car while one shops. Well, actually there is - on the sidewalk. The local market is two car lengths long.
And one more impediment to any kind of food shopping on the local economy - the stores are closed on Sunday and Monday and all the other days they close at 6 pm. Honestly, I'm not sure how working people ever buy anything.
Traditional local market shopping seems romantic and it would probably be lovely to have a neighborly relationship with one's grocer, butcher and baker. If I lived in town, I might even pursue it, as I have the time to do so. But for now, I'm sticking to the commissary and Champion market. Some day if one of the two parking spots is open, I may stop in and have a look around.