“ The bleeding hasn’t stopped in recent years as Apple’s work culture simply isn’t the best and other firms, namely the hyperscalers such as Google, Microsoft, Amazon, and Meta, are paying more than Apple was to poach talent.”
Big management negotiate higher pay all the time not because there is a difference between earning 30 or 40 millions, but because they need to feel their own "value" go up.
This is discussed at length in "thinking fast and slow", iirc.
That aside once people have kids the sky is the limit for giving them the "best life possible." Nanny, private tutors, private schools (and/or a house in Cupertino since it's Apple), college funds, house with good amenities nearby, etc. I probably missed some costs in there.
They're more normal in SF because of the school lottery system which can assign you to a school whether or not you can actually get there on time every day.