For me it is streaming, Spotify, Google Music, and Tidal. Sure you can buy HD music, but streaming is just so convenient, plus you can download the songs for offline listening.
Spotify High Quality does it make a difference with the right equipment.
You don’t need Tidal HIFI, but yes it sounds better, and of course at a price.
I have been told the sample rate is the most important factor. But I have not had enough experience to say.