Subs also add a lot of the plot sometimes. Certain quiet sounds you wouldn't otherwise hear are mentioned in the subs that can set a scene, foreshadow, or explain motives.
If I could, I would have the entire script as well, like Script to Screen does: https://www.facebook.com/pg/scripttoscreen.film/videos
One explanation might be if you're watching a 5.1 surround sound movie and playing it through your monitor's built-in speakers which can't handle the extra channels.
I work they use fewer words....it's unfortunate when it spoils a delivery several seconds before it happens.