Earlier quoted context omitted.
Everybody should have a different 4 day work week, of course. Shops are still open in the weekend.
He stated "administrative stuff" -- not "shops". Stuff that's already open on the weekend isn't an issue. And are people willing to take a 20% pay cut? I would doubt many people could afford (or wish) to do so. The entire premise is absurd, which is what I was pointing out.
I'm working 4 days a week, and that's working very well for me. So is my wife. So is my brother, and are several of my friends and coworkers. I strongly recommend it. We should be demanding better, and not discourage each other by saying it's absurd to want a better life.