I've been working my way through this 1950s podcast by someone named John Tolkien called 'Lord of the Rings'--it's a deep dive into this fictional world he created. Good stuff, really bingeable!
Podcast audio books were a thing at one point! You could download free, serialized audiobooks, usually read by the author! They were called podiobooks (and was a website of the same name) and I really miss that time. Some of my favorite authors and books come from that time.
I still have the creative common copies of a bunch of them and can share if anyone wants. Not all were CC, but you could freely share.
ABC iListen has audiobooks as podcasts. Not bad, all Aussie books. And their podcasts are great too, been listening to backissues of If You're Listening and The History Lesson podcasts.