I usually find copper ore more often than iron, so it would be good for starting when you need armor but don’t want to waste your iron ingots. Plus, a different look (especially with the gradual oxidization effect). Maybe they could make the armor more likely to be struck by lightning, energizing the wearer 95% of the time and doing some damage the remaining 5%. That could also be a good way of creating charged creepers (them lightning bounces from you to any mobs in the near vicinity).
What would be special about copper armor and tools? Unless you give it a special function, it’d just be another useless armor tier.
I usually find copper ore more often than iron, so it would be good for starting when you need armor but don’t want to waste your iron ingots. Plus, a different look (especially with the gradual oxidization effect). Maybe they could make the armor more likely to be struck by lightning, energizing the wearer 95% of the time and doing some damage the remaining 5%. That could also be a good way of creating charged creepers (them lightning bounces from you to any mobs in the near vicinity).