I had my first kid at age 34, and part of my deeply regrets not going sooner (wife is much younger). I had some serious health issues by 45, which impeded by ability to raise my kids the way I wanted.

Adopting in 40s? Will the parent even still be alive when the kid graduates college? With good luck, genes, and good diet/exercise, yes. Otherwise, likely not.

They often don’t even let you adopt at that age. I knew some 40+ yo families that adopted overseas due to age restrictions. One family adopted from China and one from Eastern Europe.

Life expectancy for a 40 year old in the US is ~80. It is very likely that with an average lifestyle the parents will be around after the child has graduated college.

Yes, that would be:

50%: some combo of good luck, genes, diet, exercise

50%: some combo of bad luck, genes, diet, exercise

Unless you live in bad parts of Africa I suspect living to 65 is not an unreasonable goal....