I'm not sure why government taxes should care whether someone has kids or not, it is your choice. If you can't afford to have kids, you probably shouldn't have kids. It's easy to be in a painful situation and come to a conclusion "Things should work this way because that would benefit me". There are other things the government should do, such as tax breaks for students, and people with student loans - fostering growt…
"I'm not sure why government taxes should care whether someone has kids or not, it is your choice. If you can't afford to have kids, you probably shouldn't have kids." Because having kids benefits everyone. It's an integral societal good with a staggeringly high individual cost. There's a reason western European countries give such generous benefits to parents like lengthy maternity/paternity leaves.
This is where economies are built. There is a premise that growth is dependent on population expansion. I think that assumption needs looking at in terms of standards of living and the future.
People are living longer but not contributing as much to society. As automation continues to take away low end jobs, we are going to have more people doing less.
We are moving from the r to the K side of r/K selection theory [1]. Our economies need to shift from quantity to quality. This is naturally happening but governments are trying to pump up growth with immigration and benefits for parents.