Knowledge rot is already a problem and has been for years – where you try to follow some links only to find they're dead, or people deleted their content. The anecdotes of finding some old problem and someone just said "I figured it out". Sure, archival won't fix that specific example, but the principle is there - we lose so much information.
It would be nice if we had a government that worked for We the People and made information archival mandatory — likr the Library of Congress already does with printed materials.