I'm just saying, if we need more people, we know where to get them.
If we really want to address population decline, we have to reverse the reasons people are choosing to have fewer children. Which starts with policies aimed to give child-bearing aged adults better financial stability, affordable housing, and support -i.e. easily available, non bank breaking childcare (perhaps even free childcare), improved income / decreased expenses to make it easy to have financial security while also having extra bedroom(s) for kids, and longer, paid parental leave.
Whereas the existing housing crunch, continued downward pressure on median and lower incomes, bare minimum parental leaves, and high cost of childcare in the US discourages and delays a lot of people from having children.
And that's a serious problem for the rest of the world! It's not a problem for the US, or any other country rich enough that people are clamoring to immigrate.
Sure, the world will eventually run out of people I guess. But there are so many people who want to come here, that time is exceedingly far away. And population decline is okay if it happens very slowly.
Edit: I'm not against the other policies you listed, I just don't think we need them because of "population decline" specifically. I'm not convinced they would even help with population decline, because families with higher incomes--ie more access to childcare, housing, and so on--are having fewer kids just like everyone else. Immigration, by contrast, really will quite transparently address the need for more people.
Anyhow yeah I don't think policy is the only reason we're in this bind, but let's be honest that we do not make it easy to be parents of young children. Various trends exacerbate this, like the fact that it's now more common to live in different cities than most of your family - which means less free childcare from families. But also many people get their idea of family sizes from what they grew up with and what their friends and family are doing, so the decline in children per woman is going to be rather sticky.
If there is a global population decline then all other societies would start declining- in that scenario the US can keep siphoning citizens
