I think if you went back and saw what really was used for most killing, you'd be shocked. Yes, the gentry, the knights were well armed with what would have been very expensive swords and daggers. But in a conflict, they made up the very small minority of the forces on the field. It was a very broad and steep sided pyramid of society, with the gentry sitting on the top and the vast bulk under them the peasants. Most peasants would be armed with pikes, maybe a mace or club of some type, or an ax in one form or another.
Swords and daggers were expensive items that only the top of the pyramid could afford. But, every man, had an ax of some sort for chopping of firewood. Axes were cheap to make, as was spear or pike tips. Cheap and fast to produce was important. And just as every peasant had a small ax, he also had a knife for the butchering of food. In the British museum there is a extensive hall of arms from the medieval period, and most of them are amazingly crude and cheap. The knives looked very little different than what the mountain man skinning knives looked like, and small hand axes were common. Conversation with museum curators was very enlightening.
One fact that will warp our view is, the gentry, the lordships, didn't use their expensive swords and showy daggers except as last resort. For a mounted knight, the lance, and then mace or ax was used. The swords may actually get relatively little use, as will the daggers. On the other hand, the peasant, when not engaged in some conflict on behalf off his lordship, will still be using his butcher knife to process food and small tasks, and his ax for the process of firewood to warm his hovel. He is engaged everyday in labor for his lordship, while his lordship sits on his rear end most of the time. Gentry did not do labor. So, the expensive swords and daggers of the gentry would survive long after the thin bladed butcher knife like knives of the peasant was worn away from use, as was the small hand axes. If mostly what we see is the tools of the upper level of the pyramid, then we can be lead to believe that is what most people carried.
Another very cool thing I saw in the British museum was, a stone mold for the casting of copper hatchet heads. This was way back, 5 to 6 thousand years old, and the one curator I spoke with said these small hatchet heads were not for chopping wood, but for weapon use, much like a tomahawk was. So even back then in the copper and bronze age, the lower peasant were still carrying a more mundane tool. There was a bronze sword on display, but he said it was for a chief of a clan judging from the engraving on it. The underlings would have been armed with more mundane told like the hatchets and spears.
JUst recently, we had a murder of a 7-11 clerk just spitting distance from our home. A nutso used a box cutter to attack the clerk, and the clerk died from blood loss. A box cutter. Then there was a murder down at Gallaudet University a while back. Two students were killed in their dorm rooms about a week apart. They found the killer, an exchange student from somewhere down in South America that was robbing and killing, using a 3.99 paring knife.
Metioning this with my son, who is a Montgomery County police officer, he told me that most of the knives they see coming in are either cheap kitchen knives, or total under ten dollar Chinese punk knives. Nothing has changed in a thousand years. Literally. MOst killing is done with very cheap stuff.