My grandparents are dead, but I doubt they would have much to say about it; they had kids (in the 1940s) because their parents would not accept anything less; religion + marriage + kids. They often told me and my parents they didn't want kids and they were supposed to have as many as possible but they only had one and promised to have more but never did.
But what great insights would they come up with pray tell? In those days (it was WOII) it was to work the land (economy), cannon fodder and pension plan (have them take care of you). What else?
"You, an existing person, find you prefer to stay alive" is not an argument for "more babies are always better". If the reason that there are fewer babies is that potential parents don't want them, then it's possible that there are exactly the right amount of babies, and the ensuing problems should be solved by other means than pressuring these unenthused couples to reproduce.
I think that creating more happy people is better, not more people per se.
We are an accidental blib in a cold vast cosmos; nothing and no-one would think of us or remember us if the earth explodes today (or if someone hits the nuke button). I 'value' my life in so far that I am not in pain and I was born in the right location with the right interests (math + computing) to do whatever I want to sit it out until I die.
How is any of it a reason to make more babies though or a sign we have a shortage just because we make less than we need to create a population equilibrium or growth?
Grandparents who lived lot more poorly or had their siblings die as babies? Lot more babies survive and their living standards are much higher. Maybe that is reasonable trade-off...
But what great insights would they come up with pray tell? In those days (it was WOII) it was to work the land (economy), cannon fodder and pension plan (have them take care of you). What else?