They're overthinking the dropping birth rate problem in the U.S.: we are just more honest about being selfish now.
This isn't a bad thing, either. Think of how many people have been made miserable through feeling pressured to have kids. Those who shouldn't have had kids wind up divorcing and leaving the family anyways.
Now, we know better than to even try a fucked up "family experiment" phase.
Obviously all the other socio economic factors are important too, but I think the margins for that have been expanding at the same rate for decades now. Meanwhile, the new increasing dataset are those who could afford kids but literally don't care to deal with it.