I imagine that the reason for adding narrative is to add another dimension that's proven to be engaging in other mediums; one akin to explanation videos like th

I imagine that the reason for adding narrative is to add another dimension that's proven to be engaging in other mediums; one akin to explanation videos like those found on Khan Academy or the educational sections of YouTube. Sometimes jumping into an explorable explanation without some guide to begin with (outside of text) may be overwhelming. That being said, I don't know how a spoken narrative would integrate into a piece of text. You would likely not want someone to read through the text as written because a spoken explanation will generally differ in phrase structure (shorter, less verbose) than written text.