I once attended a session where the process for archiving state records in Michigan was discussed. They talked about maintaining records in a digital format and having to burn fresh CDs / DVDs every five years due to the deterioration that can take place within that media.

Most interestingly, they also stated that, regardless of the digital storage, all records also had to be stored in a "human-readable" form - micro card or microfiche or something along those lines.

In the article referenced, they mention that in some ways an older movie on film is more stable and safe than a 2-year-old movie stored digitally, because of this same "human-readable" concept.

I attended that session 15 years ago or more, and still think of this concept on a regular basis.