Companies neither have to have physical offices nor do they have to be located in the Bay Area. And unfortunately culture dictates that an office is always necessary and that you need to locate your tech company in the Bay Area for dubious reasons like fundraising (which should only take a small portion of the operation of your company anyways), hiring (good engineers might come here if they agree with the lifestyle, and the job opportunities, but that doesn't mean jobs should come here because good engineers are here), or synergy (the belief that the physical proximity to other tech firms may help your company. Only applicable to certain markets at best).