Copper in Minecraft doesn’t seem to have much uses apart from using copper blocks for building and making lightning rods for absorbing the lightning strikes. Personally, I don’t find them too attractive unless I want the builds [structures] to look a certain way.
It may be too early to conclude anything about copper right now. And I think they will add more to it in the future as its just been over a year since the 1.17 update.
Copper in Minecraft can be used for constructions if used properly, like if you are planning to make some ancient theme builds like and ancient statues, cities and temples, a wrecked ship at the bottom of sea. The drawback of these structures is that the copper blocks begin to turn green overtime because of prolonged oxidation. The changing shades of the colour overtime
If used wisely and purpose and theme of the build is clear to you, then copper blocks can be great for creative builds. You can get rid of bluish green stain by using axe on the copper block for couple of times. Adding honeycomb with the copper block gets it waxed, as this wax coating prevents it from oxidation upon exposure.
Despite its loss along with Glare in Mob Vote, the copper golem would have been an amazing addition to Minecraft. Although it has been pushed into the ideas library, the return of copper golem isn’t likely. The Phantom and the Glowsquid were one of the mobs added after their victories in Mob Vote.
It would be interesting to see whether Minecraft adds some mobs or items that use copper. The loss of copper golem in Mob Vote left many players disappointed.