Investment happens outside the Bay Area, but there is, to quote CityLab, an "extreme geographic inequality."

https://www.citylab.com/life/2018/03/the-extreme-geographic-...

Or, as PitchBook puts it, "traditional hubs still account for preponderance of activity" (https://pitchbook.com/news/articles/the-state-of-us-venture-...)

NY and Boston get their share of funding dollars, too, but compared to the rest of the United States they aren't cheap places to live, either.