Paying people directly to have children seems like a horrible policy because it will have disproportionate effect on people who are less likely to be good and responsible parents.
Right now, the rich are disproportionately punished for having children while the poor are basically paid for it. How about flip flopping that?
Whom you are talking about are upstart "upper middle" who have a good wage but no capital of their own, and the rich are generally happy to have them thrown under the bus rather than face them as equals.
The method of throwing under the bus is have them overwork for a wage and then second job to waste that wage on "fueling economic growth". Not turning these into anything permanent.
Universal health care would also be a huge boon, the costs of providing health care are quite high.
In the past our society seemed a lot more inclined to share and pool resources to raise the next generation... now it feels like society will only do the bare minimum to prevent kids from dying, but other than that isn't eager to take on a communal parenting role, instead forcing the entire burden on parents.
You can be like "well then they shouldn't have such high expectations, expect and accept a lifestyle drop, and send their kids to public school" but you're yelling at a river to change course.