There are many studies showing that night shift workers experience more mental and physical health issues than day shift workers. Obviously, some things absolutely require night shifts, such as hospitals, but not stores and restaurants. Convenient, sure, but not necessary. So in a socialist country that prioritizes the well-being of workers, do you think these non-critical 24-hour establishments would exist?
Some sources on the health effects of night shifts: 1, 2, 3, 4, 5
nobody should be forced to work night shifts unless absolutely necessary, even in a non-socialist setting (because of low demand, if nothing else)