I have an honest theory, it's probably verifiable by someone smarter than me.

I think attitudes about this stuff are influenced top down by agenda - I think they're influenced top down by religion, and government, I think they get looser and more strict by agenda.

I think when governments, religions, or theocracies are trying to bolster the amount of human capital they have, you see a slow loosening and normalization, more people seeing younger humans as more adult like to justify the position.

So too, when things are comfortable in an economy, you see childhood extended, creature comforts expanded, more luxury in a society, and consequently agendas moving towards lower birth rates and values that align with that ( higher education etc )

There is a type of generational moral elasticity to this, and I'm seeing it loosen worldwide, like this, for probably the exact reason it sounds - more desperate bodies for military and economics, boosting population for replacement.

I also think this is why countries are moving against LGBT rights, and specifically against transgender people, because hormone therapy sterilizes a non trivial amount of transgender people, reducing the 'breeding stock'.

It's actually well known that there are more trans men than trans women, that is, that more biological female transitioners than male born transitioners, but they get almost no media coverage because they're not considered a threat to society in the ways they are trying to weapons the threat, but legislation covers them too, and of course intentionally.

I'm dead serious when I say this type of view goes hand in hand with anti LGBT and anti intellectualism if your goal is to nudge your people into having more babies with less opportunities. This is coming to the US and the West too, it's already on its way.

Heaven help us.