I can see the allure because it implies that every conflict could become life-threatening, therefore everybody should weigh their words carefully.
In reality though it would emphasize the weight of trained duellists higher than those with well-informed convictions. If you cannot speak the truth because well-paid professional duellists could suppress you anytime by threat of duel (or shame of declining it).
There is a good reason why pretty much every modern civilization stopped this practise: Too much was needlessly lost (see Hamilton, Fermat, many students in the 18th century Europe…).










In germany in the 18th/19th century there was the extreme duelling form of “übers Sacktuch schießen” where both duellists stood very close (both gripping the same cloth) and were shooting at the same time with pistols, but only one was loaded. Since the distance was so close, missing was impossible and only random chance decided the winner/survivor.