I think it's better, at least for me, to have 4-day workweeks. I feel that much more of my productive energy is wasted during work hours. Even with 6 hours in the morning, I won't be able to focus with the same intensity for a full day for me after work.

I think this is because I mostly use my leisure time for studying or coding. I reckon that a parent would prefer 6-hour workdays to spend more time with their kids.