I think there are two perfectly reasonable arguments about the government offering tax benefits to people with children.
One is that the government shouldn't be involved in encouraging or discouraging such choices.
The other is that they should, because parenting is tough and replacing the population is important.
For myself, I don't know which is the right answer, because each one depends upon quite different ideas about what the role of government is.
I often wish I don't know was a permissible answer to political questions.