Interesting, that is very different from the things one commonly reads about US working conditions.

I don't think employers would mind "20% less pay for 20% less work" much, but then again I've always had a contracting working relationship due to the fact that I don't live in the US. It might be more complicated if you're an employee.

I worked 4 days a week for 10 hours a day for a while. It was really nice. We’d often end up working late anyways, so even though the days were long it still felt normal, but then you also got a three day weekend every week. One of us would take Friday off and the other would take Monday off.

10 hours a day is a personal nightmare. That's very much not what the best part of a 4 day week is about. Fuck this obsession with junk productivity as measured by hours - some weeks you can get more done in one day than five, but nobody would ever entertain granting such flexibility.

I hear you! Flexibility would be the ideal.