He shared this in an interview with People. "Awards and box office numbers can come and go, but the works of art we're still talking about, thinking about, and questioning – those are the films we strive for as actors," Leo noted. According to DiCaprio , he's now taking a more thoughtful approach to choosing roles, though there are some directors he simply can't say no to.

Source:
imdb
The film is directed by Paul Thomas Anderson, whom DiCaprio absolutely worships. So there was no way he could turn down a role in his picture.