The era of falling in line

Due to the required social distancing, any kind of commercial establishment has implemented a system of queuing that customers have to fall in line with a distance of at least 3 feet. In some other countries, they say the social distancing is 6 feet. Whatever the desired distance is, as long as the people are aware of the risk and as long as they are wearing face mask then the risk of contamination is lessened.

Why do we have to fall in line when the stores are open for long? That means the stores are not open for a long time. The government had imposed a limit of 8 hours for the operation of the supermarket and pharmacy, the only 2 commercial establishments that are allowed to operate. If the operating hours will be extended to 12 hours then I guess the line will be shorter or possibly there will be no line anymore.