Why are there no familiar regional film industries in north India in contrast to the south?

I am so positive and so loving towards cinema, that only the person who knows can feel it. And Indian Cinema is love. I have like seen the top 5 movies of all regional cinemas. A lot from my mother tounge Odia, Telegu , Tamilzh, Kannada, Malayalam, Bengali. But Bollywood is considered the Big Show and face of Indian Cinema before the world. One thing that pulled me to write this post was the current scenario of Indian Cinema. And the mesmerising thing about Indian Cinema is it is not just 1 language but different other languages as well such as Marathi which gives the world audience a greater chance to witness real art.