> This one also depends on political stability.

Canada is going to be seen as similar to USA, but open to immigrants and not fascist. Will it develop enough opportunities?

Canada might be able to do that, but do also remember that the USA's president keeps talking about making Canada into just another state.

There's a big risk that everyone says "I want to be in the country that wins the next war. Therefore, China." and this then becomes a self-fulfilling prophecy because all (or enough of) the talent made the same choice.