NO, GOD NO. Possible exceptions in Fallout 3 and New Vegas because there was a repair mechanic, it fit with the post-apocalypse thing, and it gave you something to do with all those extra suits of inferior armor you find lying around. In Fire Emblem or literally any other game that doesn't take place after the destruction of all repair shops and quality manufacturers, it is distracting and unnecessary. Some people say it's to prevent you from just using the three or four most powerful weapons, but that leads to the question of why didn't they just balance the damn weapons properly in the first place.