You can replace your phone with dedicated electronics, which has some advantages, such as better battery life and generally better performance. Like I bet this thing has a better amplifier than a phone has.

And phones have their downsides. They don't last as long and are expensive. Privacy issues. And can be too stimulating and intrusive. For example sometimes you just need to know the time and before you know it you're emailing someone.

When I go hiking I can just as well take a dumb phone, a GPS and an mp3 player with me. Maybe a camera too.