It's clear that hitting enemies with a weapon wears them down. And I'm pretty sure that using weapons to destroy objects (like chopping down a tree or smashing ore) also wears them down.
But I'm not clear about things like:
- Using a weapon to hit a switch in a shrine
- Using a weapon to hit an object frozen with stasis
- Charging and releasing elemental attacks with a rod (fire, lightning, etc.) where the rod does not hit anything.
- Swinging a weapon that doesn't hit anything
- Cutting through things with no real mass (like grass)
- Hitting items that aren't reactive in any way (like a rock wall)
Basically, I'm trying to figure out when I need to go through the effort to avoid swapping weapons. It's a lot easier to use what I'm holding to whack a stasis-frozen boulder, but if it's wearing down a powerful weapon, it's probably a bad idea.