>You just keep the data digitally on some media and every few years you upgrade the tech to whatever technology and formats are "current" before the old format

>You just keep the data digitally on some media and every few years you upgrade the tech to whatever technology and formats are "current" before the old format and tech is completely forgotten. "Just". Have fun justifying the cost of re-encoding and re-archiving all of the laws of the UK every few years. The advantage of vellum is that once it's written, that's it. You don't need to go back and re-encode and upgrade to the latest storage technology. It's there, and it'll last literally a thousand years if it's stored in a reasonably dry, cold, and dark location.