What I mean by that is using a deduction, not a credit. You aren’t paying people to have kids but rather incentivizing people that are financially independent by lowering their current tax burden while they have kids <18. Their surplus of kids will more than make up the tax revenue down the road.

For poor people you continue to focus on helping with basics (food and shelter), family planning measures, and up-skilling towards becoming independent. Since a deduction probably isn’t helpful in these cases, a tax credit would continue to exist.