Comment by pjc50
There's a frame question in this, and the history of duelling. Is your image, or self-image, in matters of honor or social status more important than your life? Is it secure or insecure to risk your life simply because of an insult? To what extent does "security" in this context boil down to the capacity for violence, rather than anything else?
But duels were instituted primarily to curb vendettas, deadly street brawls, and retaliatory assassinations that aristocrats regularly engaged in. At least with a duel, the violence was limited to one death and a settlement to the honor of all involved. It was in improvement to the situation they were facing at the time.
But the idea of honor itself was a necessity for most of history, when there was no central government to enforce contracts, punish violence, etc. Your reputation was one of the only protections you had. Whether your family was known to exact revenge to those that wronged you or as weak pushovers would affect someone’s decision to kill one of you, steal your things, or make a deal with you and keep everything for themselves.
You had to show that anything someone could gain at your expense would be outweighed by your commitment to take more back in revenge.