The graveyards are full of people the world could not do without.

Elbert Hubbard (1856-1915) American writer, businessman, philosopher

“The Philistine” (May 1907)
    (Source)

Sometimes misquoted as:

• "The graveyards are full of indispensable men"
• "The cemeteries are full of indispensable men."
• "The cemeteries are filled with people who thought the world could not get along without them."

Also attributed to Charles DeGaulle, Georges Clemenceau, and many others. More discussion: The Graveyards Are Full of Indispensable Men – Quote Investigator.