> 37% top US tax rate

That's not true either. In California, you will also pay state income tax, most likely at 9.3% marginal rate - but possibly not too different in actual rate because the California thresholds are low. To continue the comparison, you'll need to consider which part of health insurance is or is not included (none in the US.) Etc. In the end, the marginal tax rates are pretty close. Meaning, shockingly high in California.

And if you do come here for work, consider also exit tax. If you are successful, you will fall under exit tax if you ever want to leave.