Grandma is either still working or far too busy living her own healthy and active life to want to be an unpaid full time nanny.

Why would she be unpaid, and why isn't family part of an active life, and why is grandma so much wealthier than her children?

Because Grandma had her mom watch her kids so didn't spend $14,400/year on infant care, and her mom had time because she got fired from her school teacher job the day she got married!

Today's mom, on the other hand, moved to San Francisco to get her data scientist/devops/whatever job (there were not any in her area of northern Minnesota and she kind of liked CA after going to Stanford) and Grandma doesn't want to move to CA because it's going to fall into the ocean, you know.

Also because Grandma can't afford to live in CA on her social security pension.

Because california is fighting the climate change by taxing her to death that would otherwise affect all those never will be born babies.

Just wondering why can't people hire some illegal immigrant girl to watch babies ? It is like one of the simplest job ever.

Caring for an infant is hard, high-skilled work and something you want to get right. "Shaken baby" is a real thing and can lead to development disorders. A hands-on attentive caretaker has a very good ROI -- healthier, more communicative toddler and child. "You get what you pay for [or do yourself]" is a real thing for the first few years of a child's life, and having family nearby, which we fortunately did, was invaluable.

How many grandma's live in retirement homes?

Back then: Have kid when 18-24, Grandma is 36-42.

Now: Have kid when 35, Grandma is 70.

Of course, 70 now is like 50 back in the day. My kid's grammy is 76 and she still takes care of business.