@evan A quick and simple answer: interop.
The RSS feed is the primary distribution tool for podcasts (not the case for blogs). With podcasts you get the full experience whatever you use to consume it (whereas blogs via RSS are almost entirely unformatted text, very different to a blog on a webpage with fonts and styling and graphics and layout). The directory of RSS feeds is essentially free using Apple’s search and discovery APIs, or those of Podcast Index (again, blogs mainly don’t have this). And the audio file plays on everything, unencumbered by DRM.
It’s all interop. It’s why the fediverse is interesting (there are many parallels to podcasting here).
Interop is the foundation of podcasting. And, arguably, why it still has problems monetising and with analytics - because it was built to be as open as possible.