I don’t think this has anything to do with the digital connection method. Having used a PS4 and a PS4Pro now to stream music via Spotify , there is just something inherently off about the sound. There is definitely some type of harshness.
I think it has to be something with the APP, and how the sound is decoded. I have my PS4Pro running through a Mutec, and you can still hear it.
It’s ok for background music, but not great for critical listening.