While streaming appears to be the prevalent method of consuming music now, physical sales of albums (mostly CDs) are still ahead of digital downloads (legal).
Comparatively, the value of a digital download is pretty small. At least with physical sales, you get pictures and liner notes. With digital download, you get a file. Not the same thing. They've tried to attach things to the file to improve the value, but it's still a file. Very disposable. And the music industry doesn't like people sharing files.
Free streaming makes more sense.