The main use for my iPod is to sit in its Bose dock at home and act as my main music library - it contains all the CDs, LPs and tapes which used to clutter up the shelves.
A mobile phone is no use for this - you can't use it for other things while it is sitting in a dock on the shelf; or if I've gone out and taken the phone with me then nobody else can play music.
Seems to me a phone is only good as a music player if you just listen to music yourself over headphones, which I do basically never.
There is still a use for a dedicated music player. Anyway, the iPod (Classic) still works fine.