In fact perhaps having a mandatory closed holiday may mean that many people wouldn't have the jobs they have now.
In terms of a mandatory closed day, how does the historical information align with the current information in relation to unemployment or under-employment?
Irrespective of any laws that are in place, there are still many owners who will threaten sackings if people do not obey the owner's whim and decisions as to the hours the employee is to work. If that means that the employees are expected to be there 7 days a week then there are many owners who will sack their staff for only wanting to work 5 or 6 days a week. There are many employees who do not feel that they have any control over this and simply comply because they feel powerless and locked in. But that is a side issue here.
If you, as an owner, decide that you want to open 7 days a week, and you have staff that are happy to do 6 days and want/desire the 7th day off, what do you do in relation to those staff? Sack them? Employ others for that 7th day who are willing to work on that day and keep the others on for the other 6 days? Pay penalty rates for the privilege of having your business open 7 days a week?
I have come across many owners that would have no problems just straight up sacking people who are not interested in killing themselves for the business owner. They expect you to work under all and every condition that the business owner puts in place - seeing that since they have given someone a job then that employee is owned by the owner. I have even worked for some such people.
As the business owner, are you willing to work 7 days a week in your own business at the expense of your family life, health, relaxation, etc? These questions need to be carefully considered in a very personal way for there are much broader consequences than you may think.