Earlier quoted context omitted.
Speculation is indeed somewhat baseless, however I think it's a bit off to attribute all joy in the world to kids!
Not all of the joy, but a lot of it. My dad was born in a village in Bangladesh. Like a real village. They practiced subsistence agriculture and didn’t get electricity until the 1990s. One out of every three children died before age 5. They lacked of everything a typical child-free American would need to consider life tolerable. But believe it or not, most were pretty happy. As of 2016, the average income in Banglade…
That's not really supportive of the idea that most joy comes from kids, or that a society without many would be joyless.
I'm not contesting that children can bring joy. I am contesting that they are the only source.