As an adult who is reducing her exposure to apps/tech for a simpler life, I have found the yoto mini amazing for my young son and I.
It has a decent speaker, we have the option of using cards, the wifi for the collection or just turning on the player and listening to some music with no ads or talking!
It would be great to have something that would appeal to adults and teens collection of audiobooks, podcasts and radio channels (add and news free) for those of us who need to disconnect once in a while and don't want Spotify which is run through the phones. Your device makes it so easy to access podcasts,stories and music.
I just couldn't see my teen son going for the yoto as it's marketed towards the younger generation, but something smaller that could still take a card of sorts would be great.
Note: I've given up my smartphone for a basic phone and I access the app when I need to via my tablet at home. For now I'll just keep borrowing the yoto mini