Each country has its little quirks. In Switzerland, my guy there gets a 13th month's salary every year as a traditional bonus. Of course, he puts in six day weeks. He came to us in 1984 at age 37, and is still with us fill time at age 73. He knows he can retire any time, but says, "what for?" I have been doing that routine (pre-virus) for decades now. My outfit could not get everything done, either if we only worked 4 day weeks. We could never pay for the benefits we give everyone if we had a 4-day work week. Maybe a factory with a few hundred workers doing jobs that anyone could do could somehow structure this, though I don't know how that would work. In my case, half of us are specialists in our fields, and can't just be replaced by putting an ad in the paper. I've been looking for someone with the necessary qualifactions to take my place for 15 years (I'm 68 now), and still have no takers.
About 30 years ago, one of the unions was pushing for this here in Germany. Four day (actually, 30 hour) work weeks with no reduction in salary from the 5 day work week. When most of the big employers in Germany pointed out that they would have trouble staying solvent under those conditions, it fizzled. If the option is getting the (pretty good) conditions most German employees have or watching your employer move to another country because he can't cover his costs (high due to benefits they pay), the choice gets easy.
Ideals are good to have, but reality always takes it rightful place at the head of the line. Just ask Bernie Sanders.