A couple of examples of DAT's point:
Back when I moved into Silicon Valley, the largest employer was Lockheed, a defense company. With decades, mergers, and moves - and growth of companies like Apple - that is no longer the case. Much Lockheed business has moved to other states. Lockheed-Martin has facilities all over the country. Much of what remains is stuff difficult to move (e.g. products whose contracts mandate the finished product be delivered by military transport).
My first job in Silicon Valley was with a defense company that made panel displays and HUDs for military aircraft. Chances are, there are HUDs flying around in A-10s that I helped test in the late 1970s. Back in the late 80s or early 90s - long after I moved on - the company was bought by another, much larger defense company, and 10 or 15 years later moved out of Silicon Valley to ... guess what state.
My previous employer is also, mostly, a defense company. The division in which I worked had been in San Carlos since the 1930s. Early last year the company decided that recruiting good technical and managerial talent had gotten too difficult. In practical terms, they realized that telling prospective employees from outside the Bay Area, "Oh, by the way, if you want to buy a house, plan on living 2 hours away. Because you may never be able to afford a house in Silicon Valley, the East Bay, or on the SF Peninsula." So they set in motion an 18-month move of product lines to PA and SoCal. SoCal is still expensive, but not as bad, and the facility into which they were moving certain products was space-qualified. Chances are, if CA went independent that company would move out, "fast", and either say, "Screw NASA," or get significant $$ help qualifying another facility for NASA work. That company is north of $16B a year, all told, so they have facilities all over the US.
While the progress of the "single-payer" insanity brings my opinion into question, I still think CA's legislature and Moonbeam/Nuisance understand that going independent would be disastrous insanity. IIRC, the first attempt to qualify and California Independence ballot initiative crumbled due to internal strife. I also doubt CA voters are stupid enough - even though they voted overwhelmingly for Hillary - to vote for secession.
