>>Audible, a monopolist ... good sense not to make its podcasts platform-exclusive

They indicate that some podcasts are free - but you still seem to need the Audible app in order to listen. As I'm sure you're aware, there's a difference between 'free' and 'open'.

As far as I can tell, the other podcast providers let podcast creators buy 'promotion'. For instance. podcastaddict.com puts promoted podcast banners up when users search for podcasts generally (one kind of promotion) or when looking through a particular category (another kind).

Up to your article, I haven't noticed as I typically search by name or just enter the RSS I've gotten from someplace like Patreon or a specific website subscription. Direct RSS entry works fine on the PodcastAddict app.

It looks similar over at rss.com - but I haven't looked closely...