The main (or only) difference to me is, by reading a book, you're making a choice as to how to spend your time. You're making reading a priority.I think it's hilarious the person who listens to audiobooks thinks it's the same as reading. By that account, I'm about to get my law degree from all the Law & Order I watched.
By listening to an audiobook, you're multitasking. I listen to podcasts. Would I choose to sit and read them? No. I listen to them, because they're an enjoyable activity while I do mundane household stuff (or work out).
But to me, that's the only real difference: One requires carving out time, something not everyone is willing to do or can do (based on sleep needs + having small kids or wahtever).