Back to Dune: having watched part one several times now, I recall no mention of a central bit of background history: namely that in this future, humankind has banned all technology that replaces humans: no computers, no genetic engineering, etc.

This is gave us the Mentats and Bene Gesserits, who learn to expand their mental powers and engage in a multi-generational breeding program.

And without computers, the only way to safely travel through space is to eat enough spice to “see” a safe route across the galaxy. Thus the vital role that it plays in holding humankind together.