I think perhaps there are two confusing messages going on here.
Broadcast radio is still widely used and doesn't seem to be going away anytime soon. There is a lot more to radio programming than listening to music. There are news programmes, documentaries etc. Wether Dave listens to the radio or not when working in his workshop is pretty irrelevant as it is his personal taste. When he is recording his videos the last thing he would want is a radio playing in the background. It would be a major PITA distraction and would cause his videos to get takedown notices all the time from copyright holders.
there are also versions of that with video. humans will probably prefer the latter, if they have the choice, and they do most of the time.
ie even when talking about bbc radio programmes it's hard for me to imagine a younger bloke sitting down just to listen to a radio documentary....
it's essentially a non-intuitive thing for humans to engage just hearing as a mean of learning etc. that's why the radio is a flop, because it's not intuitive most of the time....offcourse while driving it's ideal, but for many other purposes it's just beaten by other media, ie all visual media.
radio-draams were fun....but mainly in a time when you had no tv.
"why should i imagine if i can watch it?" is something most people will ask.
my dad listens to it because he's accustomed to it, not because it's better.
in a same way you'll see most of people in their 50s not really using the web...they're pre-web....he's pre-video...hehe...
frankly, i wonder if radio would survive if you had some other/better way to entertain folks while driving...probably not, but you probably won't find a better way either, so it'll survive...heh...
if younger ones don't replace it with their mp3 playlists...