I think the difference between radio and other mediums is the element of control the listener has over what is being played. Sure, one has the autonomy to change radio stations but the media played on said station is entirely in control of the presenter, whilst with say games and cinema, you have a higher element of control of what you want to hear and see.
I think knowing this allows the creator to create a dynamic in which they can use sound as a filtered and concentrated medium in which their message or meaning really shines through without any excess and unnecessary visual elements that may dilute whatever is being shown.
The use of your imagination and mental imagery is also needed to a higher degree compared to visual mediums. One example is ‘touching the elephant’ where a lot of descriptive concepts are introduced to the listener through the narration and description. This could allow the artist/creator to produce a narrative piece that allows for description and explanation to be the main part of the production.