When we talk about 4 day workweek, it's for some specific jobs. Not for that guy. Culturally, at least in the US, we would be happier if some people worked 7 days, 24 hours a day.
Ex: wouldn't it be better if the bank was open after work? Wouldn't it be better if USPS would show up on Sunday? Isn't it annoying that Chick-fil-A is closed on sunday?
Personally , I would love to work 4 days a week, but if the people that package and ship the product I help develop worked only 4 days, we would have angry customers. They will switch to our competitor who will brag about faster delivery.
4 day workweek is a cultural problem. We will have to give up on our instant gratification mentally to make it a reality.