That’s an interesting point. At first glance, the difference is that DRM-locked audio is not your property (or at least it does not feel like that, due to copying being zero cost) whereas the physical medium being worn down is.
An interesting anecdote that feels relevant is Wu-Tang Clan's album Once Upon a Time in Shaolin, which was only released as a single physical copy, and no accompanying download or streaming option. That's an extreme form of artificial scarcity, but that became a part of the artwork itself.