You argued that there are people in their 30s who can just afford food and shelter and implied that they are not having kids due to their economic situation, whereas 20 years ago (so in 2003) they would have had kids, presumably because their economic situation would have been better 20 years ago.

Yet the statistics show that:

1. Those with lower incomes have more kids than those with higher incomes.

2. This trend has existed for more than 20 years, closer to 50 years in fact.

Now that I've pointed this out you seem to want to argue that income is not the only factor that determines fertility rates. Certainly that is true, but given that it's true why did you seem to emphasize it so strongly in your post when it supported the conclusion you wanted to make, but when I point out the opposite only then do you decide to diminish the relationship between income and fertility?

If the relationship between income and fertility is not that significant when I point it out, then it's not that significant when you want to use it for your argument either in which case your entire point kind of falls apart.

Finally as an aside, there is no shortage of countries with either cheap or even free child care, mostly in wealthy countries such as Finland, Sweden, Norway. But guess what? Fertility rates in those countries are incredibly low.