Child tax deductions don’t even come close to canceling out the lost revenue of a potential future taxpayer over their lifetime. Especially given today’s near zero interest rate environment.

Look at it this way, properly incentivizing children would mean that the average couple with two kids would pay zero net taxes over their life. With zero rates a non taxpayer who reproduces at replacement has the same equivalent fiscal value as a childless full taxpayer.

But I (happening to have two kids) consume government services now in addition to creating the linked supply and demand for government services that my kids represent.

It doesn’t seem like “promising my kids will pick up the tab at replacement rate” is enough to be stable.

Hmm... That's a fair point. The wrinkle is not all government services scale linearly with users. For example, if there were twice as many Americans we probably wouldn't need twice the defense budget.

Helping to support people who have children is a pretty popular policy I think. People like public schools, right? Let's just do that, but more.

Punishing people for not having kids is obviously ridiculous.

But they also didn’t produce a taxpayer who would contribute to the pot.

But they also didn't take up a space at a taxpayer-subsidized daycare or kindergarten or state university.

Sure but then they mostly aren’t keeling over three years after retiring.

They also pay more taxes because they pay for schools and lots of services that those who have children take advantage of.

And that they themselves took advantage of, even the childless were children

The child tax credit is completely irrelevant compared to the cost you incur or social benefits you share by having a child.