The article says three things: "The reasons for this shift are manifold, but chief among them is the sheer expense of the Valley. The cost of living is among t

The article says three things: "The reasons for this shift are manifold, but chief among them is the sheer expense of the Valley. The cost of living is among the highest in the world.... The problem is that the wider playing-field for innovation is also being levelled down. One issue is the dominance of the tech giants." And third, government policies on immigration and education.