I love reading, but podcasts let me consume knowledge or entertainment during activities where reading isn't possible.

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.