Funding levels are lower. Salaries are lower. In physics, from the places I know in the US, about half of the faculty is foreign, and about 30% is German. This is at top universities. That wouldn't be the case if these people would find similar conditions in Europe. But it can change quickly.

Hard to argue it's lower than zero. Not to mention that low and consistent is better than moderate but at the whim of a tyrant.

Funding is always a lottery. It's not like everyone gets some, but it's less. It's more that less people get funds. So you really have to look at the average.

But you are right. That's why I said: can change quickly.