Bollywood is struggling because it makes "urban desire" films (relationships, anxiety, satire). The South makes "primal desire" films (respect, revenge, power). When you dub that primal desire into Hindi, you capture the largest linguistic market in India.
And in the battle of emotion, the versions have proven to be better —louder, punchier, and more profitable. They have broken records, created new stars, and changed the way India watches movies. desire movie trade south hindi dubbed better