Seems pointless and inconvenient for me as they usually seem to be poor quality, and can you really listen to music in the shower, and are you showering long enough to benefit from it?
Or do you own one and use for a different purpose, like swimming or Kayaking?
I got a water proof one with a suction cup, put it on the wall and it just slid down to the floor. Ended up just placing it on the sink.
It’s okay when you listen to podcasts or audio books while showering.