This is going to depend on how you do your traps.
Elf Weapon traps next to an abyss decay very quickly when they hit, but almost never hit if you use low quality mechanisms. I wore one grown wooden longsword by one step in several sieges before my marksdwarves got skilled enough to not need them and I pulled most of them.
Steel traps (mixed disc and ball) don't seem to wear. I think wear is only applied to the lesser material between the weapon and armor or perhaps in ties and no enemies use steel. You could get a Titan or FB made of steel, but it would have trapavoid so it wouldn't matter. I've only been doing this with artifact mechanisms due to concerns about jamming if that has an effect and they're not in the highest traffic part of my trap setup.
Raising spikes (green glass) don't seem to wear, and I'm pretty sure they should by material properties if they were tracked. They'd be unusable if they did, though, until it becomes possible to change out weapons without deconstructing a trap because you can't recover orphaned mechanisms from a lever or pressure plate without redoing the whole system.
Bow and crossbow traps don't wear or jam. When there was no wear the ammo reloading requirement put them par with weapon traps once you had good trap components in production. You get 10 shots from a bow or crossbow trap. How often did a good weapon trap without an artifact mechanism manage to kill 10 foes without one getting jammed in it?
Considering how cool weapon traps are, I find it fair that they need to be replaced every now and then.
Cool is all they've got going for them unless Toady One removed jamming and I missed it in the changelog. Crossbow traps are better early because you can make useful ones from bone or wood, and good ones with imported or "imported" low quality metal bolts. Raising spikes are better once you have a serious trap component production industry because they can hit trapavoid monsters, never jam, and don't block wagons. Cage traps are better because they don't produce unsightly corpses.