Plenty of scientists can and will work in industry roles or quit entirely. It’s already a crazy proposition and should not be made any harder. Finding funding can be a brutal and continuous challenge that demotivates many.
Similarly, I know several scientists who were born in Europe but were long-term residents of the US running university labs here who already moved back to Europe last year, when it became pretty obvious where this was all heading.
If I were a young unencumbered scientist, I say this as someone born and raised in the US and having lived in EU for awhile, I would be going anywhere but the States. I’d rather take 1/4 the money to not be a part of whatever disgusting thing is happening currently.