Bollywood vs Kollywood?

I like Kollywood movies although I don't understand.I watch the Hindi dubbed tamil movies.In business now bollywood is number one film industry of world.But if we see the quality of movies then Kollywood is far better than that.But according to me Tollywood is number one film industry in India.Kollywood should be at number two.Bollywood movies are just a copy of South Indian or hollywood movies.