[vmception]

Very large place and most of its advantages don't require being here.

For developing nation immigrants, US can be appealing.

For natural/existing US citizens, the US is a good starting point to leverage in more developed nations.

Salary discussion is a bit limiting, better to just be rich enough. Have capital. If you must live off of what you earn you just want to earn more from one area and spend less in another area, so the answer to that is “yes”.