I agree, but smartphones' battery life is crappy and one relies on a smartphone for more important stuff like its phone functions.
An old-style hdd mp3 player would play loud music for ~12 hours, and I'd still be able to receive texts if I ignored battery life.
With a smartphone I can only listen to music for 2-4 hours tops, and usually miss important communications when I stop paying attention and allow the battery to run out (yes, Tasker etc would prevent this but why add additional complexity?). Also, inside any heavy building/underground my signal is spotty at best.
I reverted to using a Sansa Clip + Rockbox + 64gb SD card which is suboptimal but at least better than a phone.