I am agree with most of the consensus. There are certain things that are abundant that it would be difficult to make your own. Bottle openers, hooks, rebar knives, viking style knives, kitchen knives, roses. . .
I was at a gift show and had made a bunch of rebar bottle openers. They sold very well and a young woman asked me if I sold on Etsy. I told her not yet, but I was about to open a shop. She then told me in a rude, accusatory manner that there was a rebar bottle openers that looked exactly like mine. It made me think post about posting my own. Mine were darker, straighter, twisted and shorter. I decided there was no reason not to sell them. It is difficult to vary the design for such a simple item.
If someone copied my design for my wine rack, which was created using a jig, has 7 rivets each, a unique design for the neck catch. . . you get the idea. It's much easier to vary your own design to create something unique. If you copied it, I would think that you weren't just creating A wine rack, you would be creating MY wine rack. I would consider you unethical. Plus it doesn't take much creativity to vary it enough to make it your own.