The turning point came in the early 2000s with films like American Movie (1999) and Lost in La Mancha (2002). These films showed failure. They showed the absurdity and heartbreak of trying to make art within an indifferent industry.
Whether you are watching to see a pop star survive a breakdown or to watch a director destroy a jungle for his art, one thing is certain: The story behind the story is always better than the final cut.
Stars don't go on late-night shows to tell raw stories anymore. They go to sell products. The documentary has filled the void of the long-form, unfiltered interview. Audiences feel they are getting the "real" story, even if it is edited.
Millennials and Gen X are entering middle age with disposable income and a desire to revisit their childhoods. However, they want to revisit them critically. An entertainment industry documentary about the dark side of Home Alone or the making of The Lion King offers a nostalgic rush tempered with adult understanding.
Queue up Quiet on Set if you want horror. Watch The Greatest Night in Pop if you want joy. Or try The Offer (a dramatized doc-series) if you want the business of The Godfather .