When it is some factories and some workplaces it is ok. When you try to adopt it nationwide it breaks down.

Like in hospitality, hotels are not going to stop cleaning rooms on weekends. You are not going to close restaurants on weekends. So quite some people in services also have random days in week off.

Not only that, many factories are 24/7. So not only do workers have their weekends scattered throughout the week, but they have their shifts scattered throughout the day/night. The same for certain retail.

But many do not do this, as well. It all depends on what the production target of the factory is and how much throughput the supply chain has. I think those factors tend to determine this much more than worker satisfaction.

In my personal experience, I worked at a factory that would typically run two shifts, so 16-20 hours a day in production (variable), and the third shift overnight for maintenance/cleanup, 7 days a week. But if the prices were high enough for the product at the time and the supply was in place, it would run as close to 24/7 in production as possible.

Not in my experience, no. There are some that do, such as the ones running chemical processes that can't be stopped and restarted. The ones that are basically assembly lines putting parts together can stop on weekends.

Well the most interesting part is that the preferences of workers are reflected in salaries in a free market economy. So its usually more expensive to have night shifts and more expensive to have workers work on the weekends because these are less desirable working times.