4 days gives an immediate benefit that is not as relevant for fewer days. It gives you a regular weekday off.

That means you have a day off to go to the bank, go to the doctors, call customer service for a bunch of companies that may not otherwise be open on the weekend, etc.

Further, the weekends carry an expectation of doing something. Such an expectation would not exist for the weekday off.

If we do move to a mass 4 day workweek, this obviously implies that the 3rd day off should not be the same for everybody, so basically it shouldn’t be implemented by just making Friday another day off like Saturday and Sunday. It would be much better if that 3rd day is divided for all employees between Mon-Fri.

Ye I'm with you. I personally would like to see all jobs offered as as a fractional % (with some lower limit e.g. 3 days for 60%) - this is quite common in Switzerland for example.

A 4 day week is a much easier "sell" in the short term though

3 days of weekend is 50% more than 2, for just 20% less work. The trade off is more extreme as the amount of work (or of weekend) approaches zero.

Ideally, we’d have flexibility around the denominator, allowing something like 4 on/2 off as a step towards 4 on/3 off. The maybe 4 on/4 off instead of all the way to 3 on/4 off. Changing the 7 day week is probably infeasible though… but I see equally crazy schedules from friends with shift work.

Right. It's almost as if giving people freedom to choose might be a good idea.

Outrageous idea in a wage slave society of course. What? Freedom to choose, for slaves? What nonsense. Big daddy government and big daddy corporations know what's best for you - here, choose coke or pepsi every 4 years, you are free to choose, you are free.

Like all good things, we have to iterate.