Google Play, which charges 30%, is not a monopoly either. Nor is Steam. The Microsoft/Sony/Nintendo scene is a bit less clear, but they charge 30% too.
Musicians have about the same freedom in this respect as any application developer, practically speaking. AKA, they're just as exploited (if not moreso, see other comments about how musicians are also being screwed over by studios).
Yep. One major difference is that with Google/Apple (and also Steam I believe), app makers can at least choose the price of their apps and services themselves, and they know how many units they sell. If Google/Apple are charging you 30%, just increase your price.
With Spotify, however, musicians can't choose how much their music is worth, and the payment of royalties is also not exactly transparent.
