I think the idea is that a 4-day workweek would come along with a broader cultural shift.

Imagine a world where Saturday was a workday, it shouldn't be hard as this was the case for many only a few generations ago.

We could say that it is expected that you will not only work 48hrs/6 days a week, but probably 70, 80, 90 hours likely 7 days a week!

Fortunately, a cultural shift occurred along the way, and the work week is now commonly accepted to be 5 days. Expectations of clients, managers, and employees are based around this standard.

So why can't the standard change again? Why couldn't a broad cultural shift occur in which expectations are better managed towards the productivity of a 4-day work week?

Do you think there would be a perception that I (a client) paying 100% rate for a project where people only 80% switched on will lead to a feeling that I'm only getting 80% "quality" or 80% of what it could be. (I work in a creative industry).

Employees working 80% does not mean that the company output has to be reduced to 80%. With the salary reduction, for every 4 employees there would be roughly enough cost reduction to hire another employee, bringing the output to approximately what it was before.

More hours don't translate directly to higher quality or higher output in creative fields. You might actually produce higher quality stuff if you work less. This is pretty well documented at this point

The understanding of what a 100% rate meant would (have to) be different.

Project deadlines like this are pretty bad for protect quality. Asking people to grind 80 hour work weeks is honestly stupid. It's bad for your employees, it's awful for productivity (your productivity per hour massively dives), and it's bad for quality because you're over worked and stressed and tired, which is bad for your clients. So if you want to do thing exactly the wrong way, yeah do 80 hour work weeks and serve your clients rushed half baked garbage. If you take your time and do it right, everyone will be happier. People have limits and you can't just push them passed those limits when it's convenient or when someone gives you unreasonable deadlines.

It's understandable that the client schedule seems like an immovable object, but in truth it simply is not. Of course, I recognize that it is immovable by you. But imagine they applied the same mentality shift that we're discussing for the work week. Asking "why does it have to be this way? maybe we could try something different".

Is the deadline it tied to something else that truly can't be changed, like a holiday? Then what if the project was started earlier? Or if not, then what if we were in the world where it takes N+3 weeks instead of N, but the people doing it are happier and more productive?

I agree that it's not a small step to get to that reality, but I wouldn't say it's a dream; more a vision.

> I don't really see how this can work in any kind of project/sprint based working environment.

Your work environment does sound pretty crazy, but that has nothing to do with sprints or project based work.