Salaries are irrelevant since it's close to impossible for an European worker to move to the US, work visas are incredibly difficult to get and even if you manage to get one you don't have the same careers prospects as a native.
Hard is an understatement. I had multiple friends who had offers from US companies on the table for $200k+. They all fell through because it was impossible to get a visa (however internships are easy with a J1).
The one who went the furthest worked remotely for a very well known company from France for 2 years. Even with the company sponsoring the visa, he had to wait more than 1 year to have a shot, the lottery only happening once a year. He didn't get selected and eventually the company gave up on having any hope to ever bring him.
edited: reworded to "close to impossible"