I definitely found out something similar. I've come to believe that most 'popular science', 'popular history' etc books are on audible, but almost anything with equations or code is not.

The 'great courses' have been quite fantastic for me for learning about the social sciences. I found out about those recently.

Occasionally I try podcasts for very niche topics (recent Rails updates, for instance), but have found them to be rather uninteresting in comparison to full books and courses.