[empthought]

Radio stations can pay royalties to a middleman (SoundExchange) for "ephemeral" rights, but since the mechanism of podcasting requires on-demand playback and downloading to the device, acquiring ephemeral rights is not sufficient.

I think streams where you don't pick the song that comes up next can also be licensed more similarly to radio broadcasts.

The law itself isn't really the question here; it's more the economic entities and standard agreements built to sustain broadcast use of music can't be adapted to podcast use in a cost-effective way.

This is also why we don't have the Massive Attack song as the intro to "House, M.D." on streaming services any more.