During the time my article about toilets was with a publisher for three weeks while they decided if they would add me as a writer (I was advised it could take the three weeks) two articles were written about toilets. I couldn't believe it. When I didn't get added as a writer, I thought about not publishing it but I had spent hours on it and I had written it prior to the other's published dates.
I also feared others may think of me as a copycat but I knew the truth. I think if you authentically come up with a topic, you should go for it. There's always room for more providing the articles themselves are not entirely the same.