Earlier quoted context omitted.
A properly developed, stopped, fixed, washed black and white negative stored in a box in reasonable temperature conditions isn't going to fade for a very long time.
And a digital image with a text file accompanying it describing the image format is similarly resilient. Heck, you could provide text describing the format within the image file. Also, I'll note that the comment I responded to specifically claimed that positive images last forever.
The big difference between analog and digital is that with analog, you can simply stuff it in a box and it will stay there. With digital, you have to take the time every now and then to make sure that you don't lose that stuff. And do you really think that you (or someone else, when you are gone) will be doing that properly? I mean, you will most likely have forgotten why that stuff was even "important" in a few years.
There's so much great stuff our generation is going to lose, simply because we'll forget to migrate our backups.