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 super high quality one at my work Xmas party last year. The Bluetooth in my car broke, so I keep the speaker in my car so I can jam while driving. It’s nice.