RE: What caused the fertility decline? It's not smartphones. There is a much simpler explanation.

I don't think there's a perfect time either, and it seems to be confirmed by my older friends who are already parents. The Pill certainly liberated many women from reproductive slavery (essentially) but I do wonder why the leap from "you can decide when and how many kids to have" to never having kids happened. Personally, I see it as beneficial that I am able to have sex without fearing pregnancy each time or having something like 20 kids in my life. But that doesn't make me feel like I should just not have them.

But don't you think there were always economic uncertainties? Of course, we tend to think ours is the worst time and it seems like it, surely. At the same time, people were pregnant during WW2 and after Hiroshima. During plagues and other such. Of course, they had little choice, and that's probably the true differentiator. The stress and uncertainty was there always. You just had to suck it up and brave life, anyway.