I never saw the capitalization as being about ethnic or racial identity and just due to the fact that e.g. countries or continents are capitalized.

I think it’s even more false to capitalize “Indigenous”, no?

Being “Asian” or “South Asian” are broad enough that they don’t refer to any particular ethnicity, nationality or culture.

This phenomenon exists everywhere.

(Disclaimer: English is second language, in my native language we don’t capitalize any of these words and even in English I would only do so when required by grammar, so it may impress me different than others)