Does that actually happen?
And it's worth noting that the EU is very, very different from country to country, so it's a bad idea to generalise.
None of them have at-will employment though, so it's an appropriate comparison to make.
I think the real difference here is what people value. Personally, I value having some advance notice that the boss hates me and wants me gone. This reduces my stress, and allows me to find another job before I stop earning money.
Perhaps other people value the efficiency that comes from being able to change staffing on a whim. I don't think either of these is wrong, they're just different statements of values.
And note that if we're talking about tech people founding US companies, it's driven predominantly by access to capital rather than anything else.
> Like your smartest citizens leaving to start companies in the US?
Do you have any examples of this?