That would be fine, but what is going to happen is that many workers will have to work night shifts unwillingly. It's bad for their physical and mental health.
Suppose you have a town with two stores. First store is willing to open 24 hours. Second store may have to do the same to compensate the loss of customers, and the workers there may have to work night shift even if they don't want to (I actually witnessed it first hand in my neighbourhood).
This is called a negative externality, and it is a well-known defect of free market. Even though you would think that opening a store 24h only impacts you and your customers, it negatively impacts other people.
This is a subjective opinion, but I would argue that the convenience of having 24h stores isn't worth the cost for the workers. Unfortunately, I think that I'm in the minority and that eventually we'll cross that line in Europe too, and it'll be hard to go back.
I understand that most stores would see little traffic at night, but on the other hand they'd also not need full staff, and they absolutely could do all the maintenance work at night. It annoys me similarly as "everybody must have the same two days off". So inefficient.
Knowing families where people have different working hours or working days, it really takes a toll on interpersonal relations.
That's not our current reality, the percentage of singles and childless couples is growing and they don't need to be timed with school hours.
Adding flexibility would make everything run more smoothly. Right now we're having all the commercial traffic on 5/7 days and all the leisure time traffic on 2/7 days. Offices are empty 2/7 days.
Distributing that more evenly would benefit everyone. Less traffic during rush hour, less overrun parks on your day off, less crowded super markets and packages wouldn't need to be considered lost if they're diverted to the local branch where queues are usually longer than those in front of apple stores when new iphones get released.