When I have a long weekend, a lot of times, its 'finally, no interruptions so I can get some work done', and end up working.
Guess, if you have an itch, could fill it with open source projects instead.
But I've also built the habits, over the years, of trying to make sure I have way more than just work going on in my life.
The "constantly coding on side projects" developer is pretty rare, in my experience, but tend to bubble together. (in startups, cooler tech companies or in the "innovation teams").
Somewhat related, but I do wonder what this community will look like once humans enter a post scarce (or mostly) world. Which a 4 day weekend seems like a step in that direction. Along with the other aspects of what humans will do with their new found free time. Which seems especially interesting in a consumer based economy.
The main reason is economic profit of any venture can go to pay 3 things: 1. capital invested (having an inventory of things, having done the R&D, having built an expensive factory, just represents existing wealth and assets (not money!!)) 2. labor (the people involved) 3. rent (for the land used)
With technology, and there is no indication AI is any better, capital owners get more and more of the profit of any venture. If anything, its point is to reduce the dependence on labor. So you have more people, competing for fewer spots, and you can get away with paying them less. The lower bound for what you could pay labor is just barely enough, so they keep having enough kids to provide future workers. If you start with a glut of workers, then it is a dark situation (which we are already living in, how many people can afford to have kids?)
Human preference is also wildly variable. I don't buy the constant "I'd rather not live in a city" argument that we hear because people could in fact do that, but there are plenty of preferences that people do make and it isn't like housing in fungible.
The simple model won't get us very far in estimating the actual effects and likely will actually make us make the wrong conclusions. Plus, there are solutions to many of the housing problems (which also is non-singular).