> if living with a family simply costs so much more there.

Being from Germany myself, the additional salary in the Bay Area usually compensates for the higher cost of living unless you're fresh out of University.

At least that's what I've seen for Engineers that remain mostly technical in Germany. I don't exactly know what CTO salaries are like in Germany, but I'd assume it's usually less than 200k Euros. Most experienced Engineers in the Bay Area make easily more than that in total compensation (salary, bonus, RSUs).

Even if you have to pay another 100k a year for rent/... , chances are you'd still come out ahead. Plus the weather is great.

That being said, society is a lot different in Germany, so it's not just about money and job opportunities :)