Due to casting someone who is coloured as those two spots will improve their ratings, make them seem more open-minded, accepting, etc. Look at all the major fantasy movies, tv shows, hardly any of them have a black or brown main cast.

The world has gone pretty accepting and pushing for accepting and making everyone equal, as it should be. It just isn't needed for this story, I don't see the point where they would have had tons of mixed race and been able to appeal to those people and cash in on being open. Except no, for some reason they don't think Avi will be a big enough character? For some strange reason.

I don't believe they scored these jobs 100 percent on acting skills alone, like I said, gifted.