Friend (tenured economics professor) once only half-jokingly told me, that having children who will take care of you when you are old is the most dependable retirement scheme.
There are those who don't have kids (or the kids are dead). There are also those who the kids have moved far enough away that they can't really take care of the parents like they want to. However those are not actually the majority cases.
Those cases are very over-represented on HN compared to what's typical nationally and may very well be the local majority here.
May parents have to first pay for childcare and then have to help out their parents.
They have jobs in their own, until they are too weak for those. And then, they are also too weak to be primary childcare. Mutual help do a lot, but asking them to replace childcare is unrealistic.
Edit: Goes without saying that you'll need to plan for your retirement. I fully anticipate assisted suicide being a legal option during my old age.
I have kids, but I still do not want them to spend their time caring for me on a constant basis. I hope I have the ability and physical will to take myself out before that happens. I saw what my parents gave up taking care of one set of my grandparents, I do not wish that on anyone.
They “lived” into the upper 90s (over a span of 30 years since the grandparents were 15 years apart in age) and I consider my parents to have wasted many of their best years.
You're talking about kids as financial investments and they're the irrational ones?
BTW, the average cost of raising a child 0-17 in the US ~$230k. That amount alone sitting in an index fund over many decades will provide for you more than any single person ever could.