I have been using the headphone jack on every single smartphone I’ve owned. When I was in school I’d listen to music whenever I was in the bus, when I was going from class to class, when lunchtime came around, whenever I could. When I got home, I would listen to music and watch videos. Hell, I still use my phone way too much for videos and music when I don’t have anything to do.
I listen to so much audio that I couldn’t imagine a world with a limited battery for my headphones.