> Physical libraries with the limitations of physical transfer strike are a reasonable balance. A global digital pool with instantaneous and unlimited transfer of non-degradable goods does not strike a reasonable balance.

That's a more interesting argument. I think it's valid, abstractly at least.

> Copyright strikes a balance of rights between content creators/owners and content consumers

Originally sought to, perhaps. However copyright has devolved into almost entirely serving the interests of the transferred owner who are overwhelmingly huge publishers.

It makes sense to me that a digital library poses an existential threat to the business model of those large publishers who have gradually moved away from obtaining or encouraging the creation of new original works (the original intention of copyright) to reselling and repackaging existing content over and over again. This is why things like DRM exist, not to prevent piracy, but one one many mechanisms serving this strategy by controlling how ordinary consumers can consume what they "bought", when, where, on what, for how long... so many types of restrictions all serving to extract the maximum economic return for each original piece of work they own - A library completely undermines that strategy, because it necessarily removes most of those mechanisms to function.