Long-term storage of digital assets is a problem that has yet to be solved. The failure rate of digital storage mediums I've experienced has been depressing--floppies, Zip disks, burned CDs and DVDs, hard drives--all had disturbingly high failure rates. All sorts of files I stored in "the cloud"--gone forever. Eventually, there's going to be a much better method for digital storage, but when?
The static nature of film negative storage has always been something I've valued. Amazingly, I've still got most of the negatives and slides I've shot over my lifetime. Other than some crappy Agfa reversal stock, it hasn't degraded. It hasn't taken much time and effort to preserve this stuff.