Yes, even when people copy eachother they don't have the same output. And some individuals are mighty excentric, for instance Picasso. But most people stick almost entirely to what they see and only differentiate by means of the mistakes they make, not by intended originality. From the moment people are born they start copying everything they see. With a head full of mirror neurons we tend to live our lifes exactly the same, and the differences only stand out because they're relative. From a distance we would all look, behave, be more or less the same. Copyright should be abolished. I'm all in favor of supporting artists and creators, support whoever you will out of free will, but don't limit others freedom to copy you. If we can't copy what others have done before us, then our culture is not free. It should be an honor to be copied, that means others like your idea and want to use it too. That's how humans have always lived, that's how we progress. it's what has brought us this far. Let's continue without bizarre copying limitations. If we can copy freely that means culture is free, it means we can learn from eachother, take eachothers ideas and creations, put them to use and expand upon them, sometimes inadvertently while trying to make an exact copy. This freedom will be to the benefit of us all, and the opposite is true aswel, intelectual property is to the detriment of us all.

If you don't want your work to be used by others, keep it private. Don't show it to anyone. Keep your invention in your cellar and let nobody enter. If you want to share your ideas and creations, please do so. But you can't have your cake and eat it too. You can't show what you've made and expect others to not use it as input and put it to use.