Before I had a smart phone (and before I had a car with an audio input jack), I would connect audio players into various FM radio devices so I could play podcasts in my car on my commute. If your audio player was not very loud, you would hardly hear the music over the FM noise. I eventually ran across Cowon audio players that cater to audiophiles. They could play a variety of formats and were very loud (my J3 is rated at 29mW per channel stereo with a 95db signal to noise ratio). That volume allowed me to send a clean signal into what ever device I wanted down the line. I still use my J3 for practicing music (into my Vox Amplug, Rolls PM55P on my pedal board, Fender Rumble 30 amp or into my Yamaha sound sound board to my studio monitors). I also use it for listening to podcasts in the car using my audio jack.
I can't use my smart phone near my sound board/studio monitors as every time the phone sends/receives data, it causes interference that I can hear in the monitors. I also practice in areas with zero cell or WiFi signal (so streaming is out). I guess another benefit of these particular audio players is that I don't have to worry about them phoning home my data to someone else since they do not have internet access. When traveling, I find it handy to have the dedicated audio player so when I am driving all day long, I don't worry about exhausting my cell phone battery (for making phone calls or navigation).
I have found that you can reformat these audio players when they die and can get more life out of them. I will keep them going as long as I can since I find them very helpful. Also, for those who use the older iPods, you can use Spinrite on them to make them start working again. Also, there are alternate firmware out there that you can install on some of the iPods to get more features.
I agree. I don't like the idea of your private information being at risk, just for the sake of entertainment. They should always be in 2 separate devices.