But reading is not "ingesting content" and that's it; it involves knowing how to write, graphic indicators, it engages the brain in the guessing game that is being more or less aware of the typical collocations associated to a given word, punctuation's value... for example, there are some texts that have meaning exclusively in the written medium (like the poems typed in bizarre shapes from last century), and vice versa. Very simply, you cannot say that reading a play is the same as going to the theatre and watching it: just think about actors' personal -and very different- interpretations. Likewise, is a semicolon typed out the same as a silence of arbitrary lenght? No, because a semicolon often carries some subtle meanings like being generally associated to descriptive texts/complex texts. It goes without saying that this kind of reference to a shared (between author and audience) cultural context cannot be translated into an oral rendition of the source material.

So, that's why I'm confused.

I'm perplexed. I always felt that reading and listening to audiobooks were completely different activities, I couldn't in any way group them together. Why do you?