system
Given the following post, respond as if you're commenting on Reddit:
human
[Dune] Why do they have a feudal political system in place?
gpt
Two reasons: spice and anti-computer sentiments.

After the Butlerian Jihad, humanity turned away (for the most part) from AI and advanced computers. This made trillions of people reliant on highly-trained humans to perform the tasks necessary to run enormous societies. And institutions like the Bene Gesserit and the Mentats required heavy investment of time and money, which along with a closed training tradition, made it easier for the patrons and allies to consolidate power in the feudal structure.

Spice, being restricted to one planet among thousands, also facilitated this consolidation. As long a single feudal House could occupy, fortify, and defend Arrakis (with CHOAM and the Guild's tacit support and the explicit support of the Emperor), they held an effective monopoly over the most important substance to humanity. And true monopolies, while not impossible in non-feudal societies, are much more rare.

In short, with a single important resource and human-based technologies, the ruling classes of post-Jihad humanity were able to grab power and restructure the galaxy back into a feudal state.