Radio dominated the first half of the 20th century but the advent of affordable TV sets in the 1950s seemed to spell doom for the format. Yet, radio endured. Radio was able to create a distinct image for itself, separate from TV. I have own theories as to why (cars, transistor radios and the music industry) but nothing conclusive.
It takes a long time for new technologies to saturate the market. It would have taken decades from the release of the first TVs until 80% or more of people had one in their home. Likewise, it took decades before a sizable proportion of people had internet access. It is only now that cable television is not a thing that most people pay for access to–replaced by streaming services.
As TV was taking over, Radio and Cinema would have had their place. Radio still has a place in nearly every automobile sold across the entire planet.