[pfdietz]

Texts from thousands of years ago survive only because they were repeatedly copied. There are some extreme examples like the Dead Sea Scrolls but they are the exception.

Modern acid-free paper might last 1000 years; 500 is more typical. Acid paper breaks down in less than a century.

Parchment was so expensive it was often scraped and reused; old texts can sometimes be recovered after being overwritten (palimpsests).