“The most important person in the business of filmmaking is the producer” discuss

Is this an accurate description of the role of the film producer?” Could you please make an essay outlining that there’s no such a thing as the most important person in the business of film making is the producers. That every job in film business is vitally important. I would also like you to talk about Christofer Nolan and Martin Scorsese. please use simple english and talk about pre production/ post production/ marketing the movie etc.