The fine print of that reads, only if stored at the proper temp and humidity in the right boxes without fluctuations in temp and humidity.  

It was the best there was at the time microfilm was commonly used about 100 years ago but times change. 

Since its inception, microfilm has not lived up to our hope of lasting millennia.  Commonly it starts degrading within 30 years.  The strict levels of temperature and humidity are very difficult and expensive to maintain.  Archives around the world are dealing with degrading film, disintegrating film, and lack of access to equipment.  In short, microfilm is all but dead. 

Enter a NEW Millennium!

The M-Disc as it is commonly known as is made of an extremely stable material that does not oxidize, corrode, degrade for 1000 years.  It can be read in an inexpensive CD/DVD/BLURAY player rated for M-DISC (cost $80) that can be connected to many of the billions of computers used worldwide.  The cost for the media is very low as compared to films and at 17 cents per gigabyte or 40,000 pages of black and white business documents the cost is EXTREMELY less than microfilm @ 1.5 cents per image.  Add to the costs of storage, equipment to retrieve and manage and it is easy to see that the cost/benefit of microfilm has made it all but obsolete.

M-Disc has allowed for a new storage medium and with that will come new ways to use that media.  2000 brought us a new millennium, new technologies, new ways to connect and share and analog images such as microfilm no longer fit.