Writing is not inferior when it hosts a subject being studied. To quote your example, yes, lyrics would be preferred to a song if the meaning is being studied, script would be prefered to movie if dialogues are being studied.
Atleast in the current context, books are faster to reread compared to rewinding a video, which can break your flow.
Atleast in the current context, books are faster to reread compared to rewinding a video, which can break your flow.