Has your bank mandated you to go back to office?

I mean...in this case it makes sense. Cities like SF have a huge commuter population that lives in the bay and relies on the BART to come in making commutes harder to socially distance (not as important for bankers but a critical consideration for the city as a whole). Additionally, every bank is located in an office building that is usually 30+ floors with a multitude of other companies in there (unlike NY where some banks basically occupy the whole building or a huge chunk of it). I don't see how it's possible to socially distance effectively when everyone is going to be trying to use elevators at the same time (morning and evening), and in order to effectively do an A/B rotation split you would need to coordinate with other companies in the building who have entirely different priorities in staffing/determining who goes into the office. Finally, most SF offices don't relay house any S&T staff so it's not like there's a critical need to get people back in the office. If your company does need you onsite to function they can get an exception/permission for the employee but otherwise I think California is just being pragmatic about how it approaches the situation.  

In addition to all of that, almost all of the major tech companies announced pretty early on they are going to be remote until Fall 2021 at the earliest anyways, so the private sector isn't really pushing for a return to work anyways.