For me, podcasts and audiobooks are a (near) complete waste of time.
In practice this means that I am unable to listen to most novels as audiobooks, unless the writing style either has a lot of meandering / redundancy (so when I space out for a while, I still understand what's happening) or the writing style is very active and engaging, especially first person narration without a lot of characters to keep track of. I can "get" The Martian, I cannot however listen to a Russian novel.
In practice I try to optimize for easier books on audio, especially nonfiction, as there's not a ton of characters to remember. I do find that I am able to comprehend harder nonfiction books, as many of them are organized more like a series of essays. But most of the fiction I listen to is very "pop" fiction like Red Shirts.
Even just being able to flip back to a previous section is something that paper books excel at. You get a sense of “what page something is on” (a sense of place) too, which helps the memory and referencing stick. Audio is for straight-through “reading” that doesn’t need to be as “active” because of that, and everything I read that needs to be remembered or studied does need more of an active reading approach
- Not the exact and therefore perfect reading speed as the voice in my head.
- Tonality of the narrator's voice not to my liking. Or wrong emphasis or weird intonation... etc.
- I can't skip text to find the important stuff.
- Whatever else comes to mind.
Audiobooks easily put me in the opposite state of "relaxed" and I retain only my bad feelings but zero information.
I still remember enough (at least I think I do), and it is not rare when I really enjoyed an audiobook that I buy the paper version afterwards.
When I find a good one I’ll start exploring what else they’ve read and pick those up too.
I think my listening brain is wired for conversations not structured texts.