Visual cues in movies provide a world of ways in which movie makers can accent their stories that are just not available to the authors of novels. Sound cues plays a similar role, though perhaps one that was best developed in the old radio shows. If you judge by how the public likes to consume its fiction, such freedom allows artists to make movies more compelling than novels. Still, movies will not eradicate novels since novels give their authors an ability to play with language that is just not available to movie makers. That's a good thing, too, since novels have the advantage of being relatively cheap to produce.
Many more artists can afford to have a shot at producing an important new novel than a new movie.
Computers, like movies, provide another form in which to package stories and like movies, this form needs to evolve. It's exciting today to see the first steps of that evolution. Hypermedia systems already let artists mix elements from movies with elements from texts in ways that neither form could previously support. Hypermedia systems also already provide new elements available in neither previous package. Most notably, they can contain multiple paths, so that a book can be different from each reader.