There are plenty of upper-middle-class people who live in a high cost-of-living area and are spending 50% on rent. Rich people additionally will have most of their cash tied up in business deals that won't resolve until way later.
The definition of financial irresponsibility is not being poor.
The average home price is over a million bucks there. Renting a 1 bedroom apartment is like $1500 or more a month. The poverty line for a family of 4 is something in the low six figures last I looked. The cost of living in SF/San Jose area is astronomical.
People getting paid well learn how to spend it. Also, some of the "getting paid well" by FAANGS is in options, so it's not like those pay the bills now
