Like any other media, there would be always some content which could be missing from the ears of the listeners, but that does not makes ‘podcast discover’ a sound stand alone business.
The number of users who are consistently looking for ‘hidden’ content is not sizeable enough to warrant such a business model. And this so because, there is no dearth of content.
Because of wide choice available, less people go on ‘finding trips’.
Big companies like Spotify jumping in to fray, they would try to solve the problem with technology, making discovery just a feature.
Curation and Summary based newsletter are far more interesting business models, than search and discovery!