3x isn't really 60-80% though? I understand fb median salaries are 240k usd rightnow, alphabet about 190k usd. Non-faang a fair bit lower. So offers of 70-100k eur in europe, doable in the more expensive bits, would be more like half-ish.
If Berlin salaries are 66% lower than California, then yes, it is 3x. For people like me, I would make about 80% less were I to work in Berlin vs the US.