My favourite thing about Qobuz is they have a store where you pay money and they give you audio files, like in the old days. So you can pay for your music then keep it without an ongoing subscription.
I feel I should mention Bandcamp, which gives 70% of a sale directly to the artist. In the music world that's a lot. All DRM free and in most audio formats you could want. My process when buying music is usually: bandcamp > qobuz (or similar) > if all else fails... use other means. I'll also skip step one and two depending on the artist :p
Bandcamp is great. Especially the genres I like to listen too are usually on there. Only minor inconvenience is, that the mobile app doesn't allow you to download the tracks in a way, so you can play them in another music player.
While true, and I have a lot of DRM-free music that I’ve bought from Apple, the difference is that getting music purchased from Apple onto your computer in a usable format is a bit of a pain, and it’s all lossy. Music from Qobuz can be downloaded directly from their site after purchasing, in lossless FLAC format, and many of their albums are available in high-res 24-bit and/or 96 kHz format as well.
Android phones with access to the google play store can download Apple Music, which then has DRM free music you can buy, then you can transfer to your Linux computer.
Alternatively there is an Apple Music website I believe that has direct downloads to computers, I don’t know if it supports Linux files though.