Sure it is, unless they have passed laws against emigration, like North Korea. (Of course, those laws would rightly be seen as totalitarian.)

You confuse "not committing human rights abuses" with "voluntary". Countries that are losing their best and brightest are not happy about it.

So clear up my confusion: what should we do about it? Are we supposed to commit their human rights abuses for them, by denying entry to their best and brightest?

It's possible to talk about a problem without having any solution for it. It's actually how engineers are taught to approach problems.

That is a non-answer.

What portion of this is non-voluntary?