In the case of my article, I’m referring to their use of digital compression codecs for internet distribution, not dynamic volume compression of the tracks themselves.
Apple uses AAC and their own proprietary codec called Apple Lossless, and Google uses AAC.
Spotify still rocks OGG, which I’m weirdly a fan of them for doing.
Both Apple and Spotify allow the user to toggle on or off loudness matching for tracks, which raises peaks to a non-clipped limit, and with Google seems to have this sort of function on by default.