How much impact exactly will all the flight, including the big businesses, have on SF? I don't have a good frame or scale for understanding clearly *how* bad this is for SF and in what ways.
It's very bad. People I know who live in SF have been negotiating rents about 30% lower than a year ago. Which suggests a dramatic collapse in demand to live there. A lot of landlords won't be able to cover their mortgage payments, property values may decline a lot, etc.
I believe it's bad for SF because the lowering of rental prices didn't come from increase in building housing, but rather a decrease in quality of life; as in, supply isn't meeting demand, but rather demand is dropping.
The issue has been about affordability and lack of supply. If those landlords and homeowners who’ve blocked building in order to keep home values high lose value and sell, this will open the market to those who want to build more and live there.