There are 80 million millennials in the United States between the ages of 18 and 40, which means they are all adults. If you can market to them appropriately, they are a much larger demographic than teenagers. It is even larger when you consider that many are parents as well, meaning they will influence their children. So, if entertainment is geared towards millennials, you can capture the adult market and influence the emerging youth market at the same time.
The million dollar question is: how do you market to millennials? The answer is already out there: Bernie Sanders. Whether you agree with his political views or not, you have to agree that he motivated the most apathetic generation we have ever seen into the most fanatical generation, almost upsetting Hillary Clinton. His secret is simple: Dream big and dream real.
He created a dream of a better America and he made it seem possible to millennials. Millennials are the children of hippies and grew up during the Iraq War. They were raised with idealistic dreams from the 60s, but have been faced with a bleak reality. They know that change is not easy. But, Bernie made it seem possible because he proved that he would not compromise: single payer, free college, etc. This is why Hillary lost the millennials. She was not exciting enough.
To translate this to film, you need to employ the idea of making millennial dreams come true. Take Deadpool, a very successful R-Rated comic book movie. The film answered the question: what if you made a comic book without the limits of a PG-13 rating? Wouldn't it be cool if the hero could cut someone's head off or say the F-word?
Stop making compromised visions that try to appeal to a broad market. Instead, aim to radicalize a smaller demographic like the millennials. Give them what they thought they could never have. They will talk, the word will spread. If, in development, you create something like this with an eye for a broader market, you can take a smaller budget film, make millennial dreams come true and then your own.