Have you seen Dune: Part 2 yet? I think it’s well worth watching in the cinema, it’s an extraordinarily good adaptation of Frank Herbert’s book. If you have seen it, you have probably rolled your eyes on the Freemen’s extreme religiosity and felt empathy for Chani as she spoke out against it. Nonetheless, if you are anything like me, I would expect that the religious behaviour displayed did not particularly surprise you. Disappoint? Oh yes. Surprise? Nah.
I can really recommend the video essay How Dune Gets Religious Psychology Exactly Right on this topic: