The FICA rate above for California is the social security/medicare tax. An equal portion is paid by the employee and employer. Unemployment is paid by the employer in California. Mortgage tax deductions are a lot more limited since the 2018 tax reforms. Health care is the big wild card since better employers might subsidize 80-100% of the premium while worse one hardly anything. The Obamacare ACA plans can provide subsidized health insurance for lower income workers but the subsidies taper off at a fairly low income given how much you need to survive in California.
So overall pretty much on par then. Higher net salaries in California are offset by better / more predictable healthcare costs in Germany.
Which leaves base pay, I assume the 200k in Berlin were choosen to make the comparison easier. On the surface, lower base pay in Berlin is offset by lower living costs, especially housing (I am aware Berlin is getting more expensive, it is still far from SV so).
