"Why does working longer hours not improve the situation? Because working longer makes you less productive at the same time that it encourages bad practices by your boss. Working fewer hours does the opposite."
This is evidence? Working fewer hours than what? There is obviously a point where your productivity drops off, but that doesn't mean you are producing less work overall.
What I would like to see is tangible evidence. Perhaps analyzing Jira for several companies to see the effort put into projects vs the overall productivity. Maybe set the baseline at the 40 hour week and analyze a few different chunks like 30, 35, 45, 50, and 60 hours per week. Without some sort of analysis like this all we have pure conjecture, and no way to understand where a reasonable cutoff should be.
I agree. Things like having the weekends free and getting enough sleep are really important for having a sustainable working life. But that does not mean working 35 hours per week is a must or 40 hours is a natural limit, for example 9 AM to 8 PM from Monday-Friday is a 50 hour workweek and easily sustainable. The norm in industries like banking, big law firms or management consulting is more like a 60-70 hour work week and while it is obviously not desirable, there are many people who can do it for many years.
