Because for some time now SV has been more about money and business than innovation. VCs for the most part want a massive return on investment to fit their bus

Because for some time now SV has been more about money and business than innovation. VCs for the most part want a massive return on investment to fit their business model and won't settle for niche businesses that promise only reasonable profits, no matter how technically innovative they may be or what they might lead to down the road. On the other side housing prices are through the roof, so good luck affording a garage/basement to bootstrap something in unless you're already indoctrinated into the VC/FAANG culture and successful within it, in which case you're naturally bias towards perpetuating more of the same. For this reason SV is a software-to-software-integration (not software in general IMO) innovation hub. Software scales easily, requires no physical property to build things on and can return massive profits. SV excels at building software to accelerate other software. Building software to accelerate physical situations or specific communities that don't exist in the valley requires expertise that must be acquired outside of the valley and doesn't thrive in the valley. In ag terms SV is a monoculture of software-to-software integration solutions that generally doesn't play well with other crops, with all the efficiencies and drawbacks therein.