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.
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.