It's funny the market effect, if you're, say, John Dolan, it's vastly more time efficient to spend an hour and a half talking to your buddy and get paid for it than it is to spend many hours researching and writing a 1000 or 2000 word essay on a topic that nobody wants to pay for. It's kind of interesting the psychology here: people will pay for things which take hours out of their week, but won't pay for the thing which takes 3 minutes to read, even if the 3 minute thing contains more information. From my perspective; the denser information is more valuable!
The podcasts I listen to are all from the BBC, so they're scripted and produced for radio, rather than just being people chatting. Listen to e.g.  or  and it's all on topic (and being the BBC, ad-free).
Think of it more like the old days of broadcast radio or TV. You listened to whatever happened to be on while you were listening and if you didn't hear something. . . who cares it's just entertainment?
Most of my podcast subscriptions I listen to only rarely. It's more like a shortlist of channels that have things I might be interested in hearing.
That being said, for me, the biggest downside of podcasts is that although I'm willing to pay, there's no easy method of discoverability of high-quality, ad-free podcasts.
edit: However, I jump around in media fairly often - I often go months without listening to podcasts, so I have no interest in paying a subscription fee. I just want to pay a per-episode rate and get DRM-free audio files that I can use as I wish.
I don't know what kind of talks those are, but the podcasters I listen to spend a lot of time researching for the episodes. I'm guessing few people can just ad-lib 90 minutes of interesting stuff every week.
Just like you get radio shows that are talk radio or on a specific subject you get podcasts that are more akin to radio plays, like welcome to night Vale.
Like, which conveys the situation better, "Oh the humanity" or the audio as recorded (you can in this case ignore the video, which was recorded separately)?