The advantages are that it is relatively inexpensive for individual groups of goods.
The disadvantages are extremely low quality of service; staff often do not know their product, which they sell; there is not always a good choice in the bread and fruit categories.
An ordinary state-owned store. You can always buy a minimum set of products, but you can't expect any kind of service. Very often they cheat at the checkout and because there is no product name in the receipt, you notice this only when you look at the receipt sitting at home. It is better to look at the deadlines on the products on the spot.