I think having pure data IP protected by copyright should require said IP to be uploaded to a national database in each country. After the copyright elapses, everyone can simply download from that database.
Sure, there are a lot of works to copyright every year. That's a lot of data. But we need to save all of that somewhere, so it might as well be some place that can't go bankrupt.
That already got sorted and worked for books, at least in the UK.
The British (National) Library held and still holds the duty to acquire in the form of legal deposit, at least one print of each book published in the UK.
So every single book published gets stored in there, and has been since its inception 50 years ago.
It gathers 170–200 millions unique items, and counting.
With free access to anybody, able to physically access the library.
It has a budget of less than £150 million.
I bet implementing an archive of digital content would be a cheaper and despite more technologically challenging would remain do-able with a reasonable number of techies.
Oh isn't it what the Internet Archive is, and even more?
Is that not what they've attempted to fulfill for a while now and the primary reason they haven't accomplish it is due to a legal war with large IP distributors and their armies of top paid laywers shaping the interpretation of copyright legislations?
Sure, there are a lot of works to copyright every year. That's a lot of data. But we need to save all of that somewhere, so it might as well be some place that can't go bankrupt.