You are reasoning from what might be better described as an artifact of a limited period in time that will never come again reasoning from happenstance as if it were a fundamental source of meaning.
It's trivial with backups to retain digital data forever. Even going just a bit further back in time books and vinyl can last a lifetime. What you are hanging your argument on is the lack of durability of optical disks a factor for ~40 years vs the inherent infinite durability of files forever after.
We shouldn't expect infinitely durable things to emulate tangible things that wear out because it would be convenient for rights holders if it were so.
The interests of rights holders is rarely aligned with the public. Its a multitude of barren fields that have never yielded anything because they are capable of buying art but not capable of making it. Even creatives have largely been compensated for their work many times over and are largely offering society bondage in return for nothing. More manure than fertile field. I suppose this is an overly long way to say fuck em.
Instead of quite frankly over complicated nonsense just don't legally let people use the term buy if the company can by any means whatsoever reclaim their rights EVER. They should have to use the word rent and give a duration and that duration should be enforced. The simplest way to enforce this is if you use the word buy you cannot encumber the PURCHASE with DRM whatsoever.
Current rights holders should have to provide a means to remove existing DRM. Failure to do so should imply forfeiting the entire purchase price. Rights holders that offer rentals and don't meet the duration should have to offer a prorated refund for the time stolen from users.
The sky wouldn't fall. People would still make movies, music, and write books.