On a Los Angeles Times post, somebody commented, "Californians may not miss Elon Musk, but the economy will."
I was curious enough to look this up: last year #Tesla had $24.9 billion in #revenue, and #SpaceX $8.7 billion, while #California's #GDP was $3.9 trillion. So very roughly, Tesla + SpaceX revenue was almost 1% of California GDP, although I doubt all or even most of that money actually stayed in California.
That's not insignificant, but it's not vital either. Given California's overall economic power, I think the state will absorb Musk's departure just fine, especially since there's no way to move a major industrial operation all at once. And most of Tesla's manufacturing is already outside the state.
The main economic impact of moving everything to #Texas may be to (slightly) ameliorate the famously high housing prices in the Bay Area and LA metro. Also, it will raise the average intelligence of both states. That's a win-win!