Almost always, there will be a love story stuck somewhere in there, whether it happened or not. If the person is still alive or has living family, then the movie will probably leave out any inconveniently complicated bits that might make them unsympathetic, like a habit of sleeping next to naked teenagers.
That's formula one. Formula two is when the protagonist is a criminal, like in American Gangster, Wolf Of Wall Street, Black Mass, or Goodfellas. Then we once again start them at the bottom, have them earn their way into crime, fly too close to the sun, end up caught, and usually hit rock bottom. It is at this point that they almost always end up betraying and snitching on their friends and go to jail or into protective custody, where they are forced into the humility of multi-million-dollar motivational speaking careers.
DreamWorks Pictures
Paramount Pictures
Between these two movies, the lesson is "commit a nonviolent, rouge-ish crime and you could be Leonardo DiCaprio."
And that's how, due to the limitations of the genre, biopics always end up making the most interesting lives in history look as predictable and boring as ... well, our lives.