As it's been stated numerous times in these comments, unlimited use is a potential
solution to specific
problems within the
library marketplace, but only if it can be initiated and provide fair compensation
to authors and publishers.
Historically, Apple had a behind the scenes
solution to this
problem: if your iPhone was approaching its maximum storage capacity, then iOS would just quietly delete songs it thought you didn't want anymore (
as long
as there was a copy of those songs in your iCloud music
library).