Well, if we are talking about poverty and inequality, the child may be a net negative for society, even on the ongoing basis before you consider the initial investment.

Plenty of people are still going to have children, anyway; if we at some point find ourselves short of children, we can bring the incentives back (or just have more immigration). But I don't think it's likely to happen over the long term... the days of needing to make the maximum number of factory workers and cannot fodder for the motherland are over, at least for a time. Having children is totally a hobby.