Living in the Netherlands, I've noticed that my friends who live elsewhere are shocked to hear I work four days, while my colleagues find it normal and have similar arrangements. In my case it is to working on my writing, while I know others who simply work 4 days because they prefer it and can afford to.
Many parents also work 3 or 4 days, even fathers who more and more are taking a weekly "Daddy day" where they care for their children and don't work. This ensures that their partners have the freedom to work as well, lowers childcare costs and allows them to not feel like they 'miss out'.
I saw a study once that the Netherlands has one of the highest work/life balances. I can't speak for everyone, but in the workplaces I've experienced I can certainly confirm it.