Because trying to make a movie about other cultures doesn't sell to anyone but those cultures. Hispanics aren't going out or tuning in to watch a drama about a Japanese emperor starting an all Japanese cast. Indians aren't invested in suburban black stories. But around the world everyone will watch the latest Hans Christian Anderson adaption or another action flick with white dudes because ultimately those films don't try to shove that this is White culture in everyone's faces. But the other films are very much, "This is our culture, not yours. You are just looking at it through a window."

As a result people of other cultures won't connect but the genericness of a White film where the culture could be described usually as explosions, castles and guns is easy enough for everyone to enjoy. Literally the culture everyone wants to join is the one they want to watch.

If you had every immigrant on the planet trying to get into places like Taiwan, Japan or Sri Lanka, then everyone would be watching East Asian films because that's what they want to see. It's pretty obvious once you scratch below the surface.