Where else would you move production to? Houston? Silicon Valley and California in general is a manufacturing powerhouse. Even Tesla automobiles are made in Silicon Valley, instead of someplace cheaper. Why? Simple: the talent is there, the technology is there (many of the supporting companies that make components and such), and there's already a manufacturing base there which hasn't been ruined the way it has in the Rust Belt. The Bay Area is one of the main places to go if you want electronics manufactured in this country, but it's also big for lots of other low-volume stuff.

You can't just start up a manufacturing operation in some random, cheap cost-of-living city in the US; it doesn't work that way.