seasoning they won't even use

The Spices extend life. The Spices expand consciousness. The Spices are vital to sea travel.

Also, were taking a bunch of cultural artifacts for our museums. Thanks!

For the Fremen, spice is the sacred hallucinogen which preserves life and brings enormous health benefits. For the Imperium, spice is used by the navigators of the Spacing Guild to find safe paths between the stars. Without spice, interstellar travel is impossible, making it by far the most valuable substance in the universe.

The spice must flow