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?
All my phone’s have been IP68 rated for over half a decade now, I’m comfortable bringing my phone into the shower for news and to use the selfie camera as a mirror when I shave. My case also physically blocks the charging port as an extra safety measure anyway.