Eli Bendersky's website When I'm asked "what podcasts do you listen to?", after an uncomfortable pause I'm forced to answer that "I usually don't". The full explanation is almost always too long for a brief friendly chat, but I did manage to articulate it to friends a couple of times in recent history; I think it's time to put it down in writing.
Generally speaking, I prefer Slow Media, and the slower the better. This means I'd rather read books than articles, blog posts and video talks; I'd rather listen to audiobooks than to podcasts. The same applies further down the scale; I prefer articles and blog posts to social media, and if I do listen to a podcast I favor the long-form ones.
Why? Wouldn't one learn more by spending 10 hours listening to 10-20 podcasts on different topics than by spending the same time on a single book?
While this question is phrased in a suggestive way, I posit that the answer - at least for me - is actually NO, at least when viewed strategically rather than tactically.
Consuming information is a marathon, not a sprint. It's not the case that I have 10 hours allocated in my life to consume information and I have to be as efficient as possible; the truth is that over the years, I have many thousands of hours. While it may appear that given 10 hours listening to the more condensed podcast format is more efficient, the same is absolutely not apparent if the decision is between 1000 books and 15,000 podcast episodes.
Suppose I'm interested in 20 different topics. I could read two books on each topic - 40 books in total; at my current pace of reading this would probably take a bit less than a year. Alternatively, I could spend these ~400 hours listening to podcasts and/or reading articles on the same 20 topics. It's slicing the same cake of time, just along different axes. One could claim that with articles and podcasts you could learn about more than 20 topics in a given year, but do you really want to? I'd say even 20 is a stretch, at least if by "learn" you mean at least some minimal depth.
In programming terms, it's a bit like using DFS vs. BFS to explore the same knowledge graph.
If the actual information intake is similar with the two approaches over a long time period, why prefer one over the other? This is where the quality and depth of information comes in. Books typically win on depth, since authors have put much more effort into researching and writing them than is put into podcasts or articles. Books also win on quality because they are easier to vet; when I plan to spend 10 hours on reading a book, I can afford spending 15 minutes on researching which book to read, looking at reviews, looking at samples, etc. When one plans to spend 45 minutes on a podcast episode, any non-trivial investment into research seems wasteful.
I'll end this post with a few disclaimers: none of this is a rigid rule. I do listen to podcasts every once in a while, and I do read articles and blogs posts. Some of them are of a very high quality and informational value. I'll also note that some podcasts are packaged in well-researched and in-depth series, which makes them very similar to books at this point. I'm not dogmatic about these things; just stating my preferences.