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 ran rca jacks throughout the house. These are connected to a distribution amp. Then I have cheap PC speakers plugged into that from the main receiver. This is structured wiring so they can be changed to Ethernet if necessary.
Usually I listen to the news in the morning while showering.
Another way to do it is make dongles for unused phone jacks. Just make sure they aren’t plugged into the Telco as a landline.