If your employer (W2) is in CA you pay CA income taxes.

Taxes are based on where the work is performed, not where your employer is located in all US states in aware of. So remote work solely out of your home in Reno, NV for a California company would have no state income taxes (since Nevada doesn't have state income tax).

There is a slight caveat currently if you were previously performing your work in a place that did tax:

https://www.cbsnews.com/news/supreme-court-wont-allow-new-ha...