Catalog differences aside, I think that's a nice market to analyse. Qobuz differentiates itself on audio quality, Apple on its integration with iOS, etc. I do think they ended up competing on price and product alone, except for little things.

My GF's Spotify makes great playlists, but they deleted my account twice and I'd never go back. So in that sense I'm willing to pay extra for customer service, which many of them don't care for. That's an interesting differentiator.