We may be able to get by with lower salaries than America if Americas immigration system continues to lag. It's easier for potential AI brains to immigrate here than the States under the current climate. I do agree that this is only of limited advantage, but it's something.
I feel like because of structural and tax issues with our society, American style salaries will never be a thing here. That probably means that we will never be the tech power house that America is, but I think we can compete pretty effectively with Europe in getting the brains who, for whatever reason, choose not to go to America. And hey . . . second best ain't that bad.