I would love if you could repair a weapon. Let's say a grandmaster swordsmith makes you a "unique" (I forget the name for skill 100 with special patterns) sword and you name it something snazzy. Why not make it so a grandmaster weaponsmith (a weaponsmith at x skill can only repair weapons that were made at that skill level and below) is required to repair it for you? A reasonable amount of materials (Depend on durability) to repair vs make a new one is fair to me. The grandmaster weaponsmith could also charge money to repair items. It would add that level of bonding so to speak and it means something to put the best materials possible into the sword (and seek out 100 skill to get max dura).
Then when you kill someone and take their fancy weapon, it's almost like a trophy. Not to say everyone's weapon is valuable but it adds that layer of personality. "I got player X's awesome sword and now Im going to run around with it".
IDK, it's not necessary but just feels like it would fit in MO2 and add a layer of depth for weaponsmiths. The players can choose to NOT repair the weapons and just continue mass producing like they do now.
Oh and while we're at it, let's also apply this to armors!