Every media type has a natural “grain”, a gentle structure that tugs and shapes the work within it. You can write a novel about your heroine that has piercing blue eyes and the audience with believe you. In a movie, to convince the audience that your heroine has piercing blue eyes requires that you go out and find an actress with piercing blue eyes and this is significantly more difficult.
The natural “grain” of movies is hucksterism. It’s easier to portray an artist who is a talentless, pretentious hack who exploits a gullible audience than it is to portray an artist with genuine talent who receives the accolades they deserve. It’s easier to show a motivational speaker who only speaks in pseudowisdom than one who says genuinely wise things.
Literature is the medium of heroes, of people who are admired by others because they do great things. Movies are the medium of dupes and cons, of the people who are admired by others despite having no discernable talent. Is it then a coincidence that the rise of the long form novel coincided with the spread of modernism with it’s exultation of progress and cinema coincided with the move towards post modernism and the admiration of aloof cynicism?