And government aid is not just for unfortunate events, it's used to promote desired behavior. That's why there are subsidies for companies developing green energy and EVs, for farmers growing certain crops, for animal feed (very frustrating as someone who always has to pay more for veggie burgers), and many other things. Clearly, though, the US doesn't value parenthood very much because the monetary incentives simply are not enough. I guess when you know your replacement rates are kept afloat by immigration, you don't care much if your citizens have kids.
It's funny that you say being social is easier, because what I see is the opposite. Being a parent isn't a panacea for socialization. It can be very isolating when your childless friends can drop whatever they are doing to go have a good time (so they don't bother to make plans, they just go) while you have to secure a babysitter just to get a quiet dinner. Your friends have to accommodate you, and many will not.
As someone who is currently childless with both new parent friends and not-so-new parent friends, it's very clear to see how much simpler it is for the ones of us who don't have kids have to be social or follow their own interests.
I feel in no way compelled by any law or incentive to have children and am in fact dreading the day my wife is serious about having them, because I have seen first hand what it does to your bank account and your personal life.