I personally take a 20% pay cut to work a four day work week. Of course at any moment I could negotiate a 25% raise by going back to 40 hours a week. Why do I

I personally take a 20% pay cut to work a four day work week. Of course at any moment I could negotiate a 25% raise by going back to 40 hours a week. Why do I do it? Because there are plenty of things I want to do with my free time and I need time more than I need money. I want to trim my bonsai, I want to go bouldering, I want to go the gym, I want to have time to shop without the after-work rush, I want to work on hobby coding projects, I want to read, I want to solve differential equations, I want to watch TV, I want to clean my house in leisure. So... why would I produce 25% more for my employer in exchange for 25% more money that I don't really need to lose that time doing things I love? Is anyone's life so simple that more personal time equates fully to just more tv time?