Can San Francisco save itself from the doom loop?
No. Doom loops are products of demography.
You need a certain number of people capable of doing enough valuable work and willing to accept a reasonable tax on the value of that work in order to run a functional city, let alone a metropolitan one.
As talent and corporations leave, these demos get worse. As they get worse more companies and people want to leave and the drop accelerates.
This leaves only those reliant on the city/area and drives away the actual producers of value that previously kept it alive.
The trick will be ensuring this doesn't occur again after the inevitable collapse.
Other municipalities should take note:
Keep your % of competent high earners high or your city will die.