I fundamentally believe that concern with how many children are born in absolute numbers is inherently an intrusion of the state into a sphere that should be entirely up to a citizen's private life.

What if the state is birthing the children?

When they say, "people should have more children" they mean "we need more bricks for the bottom of the pyramid so I can keep my place higher up"

The people control the means of reproduction

Yes, it will have economic effects. States should start from the position that they need to find ways to cope and prosper /no matter what/ the population growth rate graph says, and distance themselves from managing it or even endeavouring to.

Yeah - I'd be concerned if people were having more or fewer children than they want to have. But it's not a bulk issue.

I 100% agree. I more or less have no take on natalism other than that people should be able to freely have children, and if we're concerned about an employment base the answer to that is unrestricted immigration