If things were based on pure economics in a vacuum, there would be no good SF based tech jobs. There'd be middling salaries for developers across the country, and probably actually the bulk of the work would actually happen in say latvia or laos. Instead, we have weird layers of cultural assumptions that keep many of these jobs onshored to the bay area in particular, for no reason at all really. Even with the AI tidal wave, companies still want butts in seats in SF for some reason.