Some people might say that there's nothing left on the planet to write about that is original as it's all been done before. Well, yes, to a certain degree I would agree with that. But, on the other hand, it's not been written by you or me. We are individuals with a unique experience of life. No-one will ever have the same experiences, go to the same places, have the same ideas, motives, thoughts and inspirations as you or I. You can, therefore, bring freshness and originality to your articles. No-one can do that but you. If you asked ten writers to write on the same subject each of those writers will produce a different article. The content might be similar, but because each writer will bring their own blend of experience and opinion to it, they will have an originality about them that editors will love.
So instead of thinking, 'Oh I won't bother writing about that because someone else has already done it,' look at the subject matter from a different angle, from your perspective, and see if you can come up with an even better article that sparkles with originality and freshness that will have editors snapping it up. If you allow yourself to give in to your writing devil who is telling you not to bother writing about this and that because it's all been done before, you will end up not writing anything. Not a good place for a writer to be in!
Happy writing and give your writing devil the heave ho - I wonder what you will achieve once he/she's gone?