I heard this quote recently as an explanation for the low and still declining birth rates. Without God, nation or a grand idea, there is nothing to fight and die for and thus you focus on surviving and enjoying whatever earthly joys you can get. That takes away any drive to procreate and continue the bloodline into the future.
Things being expensive are not the reason why people don't have families and related policies make very little difference.
Totally anecdotal of course but just my 2 cents.