Maybe you have to look at the intent of the artist/songwriter/etc. I think a more egregious example, historically at least, would be the minstrel shows where white men performed in blackface, Al Jolson being perhaps the most famous example of this. A product of the times I guess.

Re it being egregious, what would you say that Jolson's intent was?

Honestly, I don't know. It could be that Jolson was just a product of his time. In the 1920s and 1930s, it was in style to make fun of minorities, particularly African-Americans, so no one ( or at least no white persons) batted an eye when someone would go on screen in blackface and do some ridiculous caricature. It was an era when the KKK was popular enough to control the government of Oklahoma for a time. Racism was more obvious in the movies but there are plenty of racist songs from the early period of recording as well.

The black character in Ol Man River.

Sure, so a particular fictional character.

A black man's perspective, like I said.

I don't think there's any good reason to believe that Jolson was "making fun of" anyone. Not that I agree that "making fun of" people should be verboten expression in the first place, but I don't think there's any good reason to believe that that's what he was doing.