Spotify takes 30 %, too. The 'one third' in the headline is just rounding.
And the question should be if digital markets and platforms should take 30 % or not. Because every platform does so from Steam to Apple App Store to Spotify.
Besides that Spotify offers more than Steam imho. Playlist creation, discovery algorithms, individualized playlist generation, AI DJs and if you consider Steam to also be a social platform, Spotify is too.
Even the smallest artists are making more than 1000 streams yearly. The only ones they are hurting are AI generated songs.