1) Salary change not worth it. Switzerland already pays a lot and for me it's the sweet spot for quality of living / disposable income. Considered the cost of living in SV I would be saving more or less the same amount of money regardless of the bump in compensation.
2) US working mentality is not healthy IMHO. Luckily I was able to experience the workaholic culture that my peers in the US show. Answering mail or reviewing code over weekends, late at night for their timezone, ... . If I am expected to do that to meet expectations thanks but not thanks. I value my work life balance too much. This compounds the 10/15 paid holidays days year vs 25 I currently enjoy.
3) I don't like commuting for that long. The 101 in SV is a nightmare and, honestly, I am not sure how people do that to themselves like spending 1+ hours each way every day. In Zürich it takes me 12 minutes door to door using public transportation.
That will be the case (riding a comfortable shuttle with WiFi) if you work in Mountain View and want to live in San Francisco (65km away). You can either move (much) closer to the office or just work in San Francisco (more likely if you find another employer).
Moving much closer obviously makes the monetary aspect of the proposition much less enticing since the rent is ridiculous. And if you happen to hit peak traffic where everyone is trying to leave the office, even being physically close might not get you home in 12 mins.
I have lived within 15 mins car/public transportation of the office(s) I’ve worked at in SF and SV for years and paying the rent has been more than worth it.
In a way, there's a selection bias: most of these employees already knew that they could get more in the same company by just relocating to a US office, and that it's not that hard to do. If they were still in Europe at this point, it meant that they had real reasons to stay.
Believe me or not, very few people accepted. Surprisingly for me.