As an amateur book conservator I'll tell you that books DO age, some far faster than we do.
Cheap paperback books may not last 10 years before they yellow and become brittle with age.
Even the most precious books we have require gentle care and protection for them last longer than a single lifetime.
The oldest book in my collection is not quite 300 years old. It has been rebound twice. The professional that rebound it recently told me that if I kept it protected in a book box it would last another 300 years (if it doesn't I get my money back :smilewinkgrin: ).
Besides the physical aspects of the book, there is the language which constantly changes. It's hard to read a book written in the 1900's; language was slower and flowery, they took their time elaborating a point. Books from the 1800]s are even tougher to read.
Today we want the author to get to the point and move onward at a quicker pace.
But the message of a great book will last as long as the words can be transmitted or copied.
The tragedy of burning a book or even tossing a book out, lies in the loss of its message to future generations.
Rob