I took a look at
4dayweek.io, and I'm impressed that there's enough jobs like that to warrant a web site, but I also don't want to do any of the things up there for four days a week. (Also, a some of those are "36-hour week" listings, which you can just get by having a 40-hour week job and stopping early each day.) That feels like it's a bit unreasonable of me, but I know from actual lived misery, that it's best for me to not get into situations I feel like that, unreasonable or not.