I would gladly move to a state with a single-payer healthcare system and I have never considered leaving my state before in my life so it might not be quite as one-sided as you think
Me and my Wife are already fed up with the high taxes here in CA currently and we get pretty much nothing for them. We are already planning on leaving CA for good as it makes zero financial sense given we can both work anywhere we want.
This potential tax hike would probably be the proverbial "nail in the coffin" to the state of CA. Just for us we would see our taxes go up the equivelent of doubling our mortgage payment, that is complete insanity and I would expect 80%-90% of all the high earners to flee the state causing its finances to drop off a cliff.
If your net take-home pay goes up (or even stays the same), why would you care if the line item called "CA tax" goes up while the line item called "health insurance payment" goes to zero?
Because my line item - insurance payment is only $2350 out of pocket me for the year, the tax hike according to what we make (delta to our current taxes) would equate to a years worth of mortgage payments, which is a gigantic difference. In addition california already has a low income health plan called "covered california" so low income families are already covered without the need for doubling taxes.
I am certain that your "insurance payment" is missing out on the portion that your employer is paying. The big tax increase that the headline is talking about includes that. If you look at your paystub you can find the total cost, and I am sure you will be shocked at the number, it is very likely over the costs we are talking about here.
The headline hints that families would be paying those additional taxes, but if you read the details most of the additional taxes are on companies (and the best points that the article makes are about how those are structured in ways that may not make sense). They are trying to mislead you to be outraged in the headline, and it worked.
So the taxes that you and your employer pay would increase (that is what the headline is saying), but much if not all of that would be offset by the costs that you and your employer are currently paying.
38% decrease in people moving to California 12% increase in residents moving out of state last year.
In San Francisco Bay Area, it's even more stark. There was a 45% decrease in entrances from other states to the Bay Area and a 21% increase in residents leaving for other states.
People halting moves into a dense population center because the city shut down for covid is not the same thing as people "fleeing in droves for taxes". There are absolutely some people doing this, but you are making up connections and this is a lazy talking point.