Because movies today aren’t based off of what the demographics of America were when you were a kid. Because any product ever created has been created to cater to the market or markets which it serves.

By your logic they should’ve never made the film war horse because horses on the battlefield weren’t a thing by the time you were a kid. But they did, and they used horses cause it’s accurate of the times they were portraying in the film.

If they make a movie based on a Japanese manga full of Asian characters, they can use Asian actors and actresses because that’s accurate to the manga they’re trying to portray.

Dragon ball Z was hugely successful in America. Every kid in America was familiar with it. They didn’t need to recreate the entire series with white characters for it to be successfully shown in America.

Again, plenty of movies aren’t remotely related to what the demographics in America are. The fact that you think white skinned people have to be the stars of American films shows your innate biases. You’re digging yourself deeper with every comment you write.