Well black people can be citizens, they can be born in the UK. In additon, which "Native Brits" are indigenous to the UK, and do we need to look at how much French/Roman blood etc.?
White Europeans are of course not native to US or Australia.
White Europeans are of course not native to US or Australia.
None of the populations of North America, Australia or the British Isles are indigenous by any neutral definition of the term. Populations have migrated and settled these regions over thousands of years.
You are a native of a nation if you are born within its borders. It is that simple.