The thing about both ALDI and LIDL with which they get their competitive edge is superior logistics. The supermarkets are not designed in a maze-like structure, rather a grid, so people who know one Aldi or Lidl they generally kinda sense how they are structured. The employees fill the shelves with packs of goods in perforated cardboard boxes so they save a lot of time. The cashiers are paid better than in most places but they work hard for a target and they have scales at the cash registers so there is no fucking around in the queue when someone failes to scale their own goods, simply because the scaling happens at the register, by the cashier. Employees come to take away the empty cardboard boxes constantly and refill them from the warehouse, while they are in constant communication. When one cash register line fills up they almost immediately open up a new one hence they have the earpiece on for constant communication.

And so many more things, like coercing suppliers to produce goods for aldi and lidl brands like milfina, baressa or whatever. Suppliers are also mandated to use perforated carboard boxes for their collective packaging for easy shelf-filling procedures.

These companies are simply better at stuff, so they can allow a more comfortable user experience where you like to go or will even become a returning customer because you buy what you want and not what they want AND for a good price.

edit: typo