1) I've found places in the bay for way less than what they were saying, even without roommates. Its like 2k for a 1br in Lake Merritt, which is 15-20 minute BART to SF.
2) Yes startups that are pre-seed/ pre-series A will have crazy hours, but any big tech co. will be pretty close to 40 hours a week. My team is pretty big about work life balance, and we work at a place infamous for not caring about it. I generally work 9-5, with whatever wfh I want.
3) See point 1. Granted if you want a house, it'll be more/farther out, but apartments can still be had.
4) Money is better in the US. I currently make about 160k USD, which is more than pretty much any European Dev will make.
6) 300 CHF is still 6x what I pay for healthcare per month. I currently pay 46 USD per month for (from what I can tell is excellent) healthcare, vision, and dental.
There are a lot of legitimate criticisms of the bay area (expensive, local politics are fucked, everyone is a tech bro, etc), but some of these are a bit ridiculous and not very indicative. There's a reason why the bay area is a desired place to live, and why I personally am trying to move back there.