Just to be clear: competent people exist everywhere, in the USA, Canada, UK, New Zealand, India, Japan, China, Argentina, Korea, Luxembourg, Sweden, and everywhere else.

What matters is where these competent people want to go.

When people want to leave, that means there's something lacking at where they are currently.

My opinion is that every place must create an environment where their best brains want to stay there (without being forced to, of course!). The whole world could be better due to that.