We've had data storage that lasts for millennia for several thousand years already. The invention of millennia-long storage more or less coincided with the invention of writing.

There isn't really a benefit. Our durably-stored several-thousand-year-old records suffer from various problems:

- They're hard to understand.

- They tend not to be relevant to much.

- Most of them have gotten lost. They're not gone, but it would be extremely expensive to find them.

Interestingly, these are the same problems that occur with stored data of much more recent vintage. But they get worse and worse over time, and the fact that the storage medium itself doesn't degrade does nothing to help. It tends to make those usability problems worse by giving people a false sense of security that the data is still there, until the cost of recovering it becomes too great and for practical purposes it isn't there anymore.

If something matters, it will be stored on ephemeral media and recopied over time onto more ephemeral media.