Film, at its best, does belong every bit as much as a Beethoven symphony, a Turner painting, a Wright house, or a Shakespearean tragedy (examples given by Kenneth Clark in his Civilisation U.K. tv series). There are many film examples which are civilization/civilizing landmarks in affecting the Western world or cultural consciousness such as The Godfather, Lawrence of Arabia, and Citizen Kane.
Usually these works are very deeply affecting (emotionally, mentally, spiritually), change the way we look at ourselves helping us to understand better and significantly Nature, the world, life possibilities, and human nature or human experience. There is a largeness of vision and artistic control of purposeful, thoughtful design that transcends movie schlock of the day or even moderately well-made, or justifiably popular flicks. These films are clearly works of art with excellent deployment of film elements. They have larger views that move us, that we easily identify with, or that change our heads about what art, movies, life, and people are and might be/come.
In and of themselves, there is a heightened realization of the spirit of man, large leaps forward, and expansions of human consciousness. In that sense, then, we can speak of great films as artworks on a par with some of the other greats mentioned above. These have contributed to Western civilization and to an enlarged sense of what is humanly possible.