Breaking obsolescence into separate playback and fidelity components is helpful. The other point about the use of high-fidelity formats is that it lends itself to a LOCKSS* strategy that could keep individual works from becoming as scarce as your old 78 up there. If the publisher has the only high-definition copy, what happens if it gets lost, damaged, or intentionally destroyed?

When obsolescence is brought up, I always find myself thinking about the related problem of access, in the sense of open standards vs DRM, but also in the senses of “I can afford access to this information with its associated technology, but you can’t,” and “My human-readable physical photo albums are more accessible to my two-year-old and my non-computer-using mother than any digital format could be.” So maybe there are some similar distinctions to be made in that realm….

*Lots Of Copies Keep Stuff Safe