Trevor G. answered • 04/23/19
B.S. in Film Studies with 8+ years of experience
In short, it's to make a movie more compelling/more relatable.
Longer answer:
Every movie is 50% video and 50% sound.
Even going back to the beginning of the industry, silent films have always had some kind of sound associated with them. Maybe a sweeping soundtrack, maybe the hustle and bustle of city sounds... there was always--something.
Space doesn't have any sounds but movies do.
Your average moviegoer wants to see and hear something for ~1.5 hours. They'd be less pressed to watch something of that length without any sound.
Sure, you could take creative liberties and just have a film score play underneath an otherwise silent film. But that's more a creative decision than anything else and the film industry typically isn't willing to put big bucks behind highly creative projects unless you can make a great movie for less (Christopher Nolan routinely comes in under budget and without a ton of reshoots or extended principal photography). A good example of the industry saying no would be Mad Max: Fury Road. Originally, George Miller wanted to make the film silent but was told that he couldn't do that.
Hope that thoroughly answered your question!
Feel free to ask anything else. :)
