Maybe not on a $3 million 5-bedroom mansion in the hills, but with $500,000 1 and 2-bedroom condos, 20% down payment is $100,000 k, which is affordable by a high level engineer or product designer making $500,000/yr, especially if it's a power DINK couple making close to $1mm/yr. Whether they want to invest in housing there is another story, but let's not pretend the upper class is priced out of Cupertino.
There are not many of those. (Not many condos in the US in general for that matter, since they're pretty discouraged by housing laws.) Wonder how many 10s-100s of bids there were for it.
Anyway, I'm not accusing Cupertino residents of being upper class, I'm accusing them of being old.
"Some of them are old" is a different statement than "None of them are young", but I see your point. It's true to the point that the local elementary school was or is closing down due to lack of enrollment.
Eg https://www.zillow.com/homedetails/20488-Stevens-Creek-Blvd-... recently sold.