I am just a layman when it comes to this kind of thing, but I notice that many articles online claim that variable bedrock depth explains why Manhattan's skyscrapers come in two distinct clumps. If this is true, then it seems strange to me that NYC professionals would ignore bedrock depth in SF out of pure ignorance.
Galaxity|4 years ago
They also said the shallow bedrock didn't force them to stay there. It isn't much of a problem to drill deeper and a number of early skyscrapers were built elsewhere... It's just that people wanted their skyscrapers to be in midtown and downtown.
https://buildingtheskyline.org/bedrock-and-midtown-i/