Being unemployed seems like a very different situation from having one more day off per week. If I had one more day off, my life would be the same in terms of social connection, except that I'd have more time to relax, recharge, and engage in solitary hobbies. The people I've worked with who have had Wednesdays off certainly weren't bored on their days off; they were giddy and triumphant on Tuesday afternoon and would spend the free day kayaking, fixing around the house, reading, etc.
If I ever get married I'll put an alone day clause in the contract. I love you but I need to get away from everyone. It can be hard to say without seeming like you're saying "you're annoying me" but there's just something different about being alone. At least if I have a meditation bench, there's that.
The problem is that if you have kids, it's going to be almost impossible for both of you to get an alone day and still have time to do things together.
Yep, that's probably a big reason people just aren't having many or any kids these days.
Back in the "old days", people lived with multiple generations under one roof and with their extended families. So raising kids was easier because you had a lot of help: grandparents, uncles/aunts, etc. Then the "nuclear family" came along in the 50s and things started falling apart. It was OK for a while because women were relegated to near-slavery, but then things changed and we had two working parents, and then there wasn't enough time to parent properly.
I can attest to this. I have a four-day workweek, and Friday is hobby day. The weekend is usually spent hanging out with friends, since they also don't work weekends, but Friday is perfect for catching up on hobbies. I strongly recommend it.