Jane Austen only ever wrote about what she knew about.
And there are MANY objections to the racism, sexism, religious bigotry and outright plagiarism within Shakespeare (and other dead white men).
And yes, First Nations people or Native Indian Americans also voice a lot of anger when white people write stories which allegedly represent them.
I also wonder why Rick Riordan can have half a book written from the POV of female characters but never make one of them the eponymous hero.
And there are plenty of fancy dress costumes without having to use black face racial appropriation.
So - yes, there is definitely a point to the argument that white people trying to represent other cultures is just another form of white colonialism. We may have stopped running the government, but we still think we can tell their stories for them.