They have longer battery life, more predictable performance, and a wider range of operation parameters.

I’ll always prefer my specialized equipment for serious music listening, my ebook reader for longer reading and honestly pen and paper for serious note taking. They perform better and I get more performance with less effort.

I have an iPhone that I believe was damaged in this way.

So you’d probably want a purpose built bike computer, an older phone that you don’t care about the camera, or perhaps there are fancy vibration dampening mounts that could work.