Play stupid games (40 years of anti-natalist policy, dilution of labor bargaining power) win stupid prizes.
1. Supplementing housing prices or guaranteeing mortgages makes them unaffordable. People cannot afford to have kids
2. The severity of the divorce process makes people unlikely to want to marry. Marriage rates have declined. Less marriages, less kids.
3. Helicopter money keeps real wages down. Cannot afford to have kids.
You may say these are not explicitly "anti-natalist" but in effect they are.
We now have the internet available 24/7. You can have live conversation with people around the world at any time of the day or night. You can get a lot of your sexual and emotional needs met through some means other than a relationship in meat space.
Historically, the default assumption was you got married and presumably the result would be children. We had a lot of cultural norms, like shot gun weddings, to deal with the reality that birth control mostly wasn't a thing and there were consequences to getting your needs met. This was part of why we generally insisted on standards like no sex before marriage.
A lot has changed over the years. For good and for bad.
All of these changes to the tax code have increased the rent which wealthy property owners can extract from younger workers without having to work themselves, at the cost of increasing the tax burden on younger working families, so that they cannot afford to have as many children as early in life.
For US federal policies that are explicitly pro-natalist (and not merely not explicitly anti-natalist), consider the Child Tax Cred, Child and Dependent Care Tax Credit, Family and Medical Leave Act, mandatory maternity coverage in the Affordable Care Act, among others.