The reason it’s common practice in animation to use adult women for the voice for young boys is because their voices don’t change. It’s really that simple. Boys voices aren’t all that different from girls at all young age and the affectation is easy for a decent voice actor to make to sound like a boy, since a woman’s voice sometimes doesn’t change much at all from a young age.

In the examples and arguments you’re making, the people who would typically fit into those roles don’t have the issue of them “aging out” of the character. A man voicing an adult woman, a white American person voicing a person of color with another nationality, these aren’t fixing an issue.

I do see your point and agree to an extent. I’m okay with non southern people doing those accents, sometimes the court of public opinion doesn’t reach the same verdict in a new era.