What violence is, and how it is portrayed in fiction? I mean honestly, violence is many times portrayed to be something kind of weird, like an extension of the characters emotional state, some kind of "discussion", like when characters meet each other they clash blades. Hell, one of the most annoying things is that violence is sometimes even used as an hello, like someone is attacking you suddenly, but later you become friends or the other party realizes that you are friendly.
But that is not something that violence is and how it works, violence is brutal means to and end. It is sudden, it is chaotic, it is violent, you can't know who comes out at top, even a superior fighter can lose because of bad footing.
And that is exactly how it works in Dune (focusing on books mostly). The violence is usually heavily premeditated, it is plotted meticulously and then executed in a fast and sudden manner, so that the other party has no idea that is coming. Even Tsun Zu said that war is deception. An attack you know is coming is a sloppy one.
In Dune almost all violence outside of duels is a sudden outburst meant to annihilate the other side when they least expect it. You know that there is trouble when your friend gets suddenly lazered in half, or an atomic weapon is used nearby, leaving you scarred for life. Even the important characters don't escape this, they don't die in glorified sword duels, but in seemingly random outbursts of violence.
Paul (the main character) says it many times, that even if he is a superior fighter, losing his duels is still probable and could very well happen. But honestly, that is just all talk, especially when he constantly leads a band of fighters to fight in the front lines, and comes out unscathed. Kind of similarly, good fighters constantly win and mow down lesser fighters with ease, so hand to hand combat is kind of romanticized at times, I have to admit that!