When a question is closed as Duplicate, it is marked:
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
However, this is slightly misguiding. The question might be (on the surface) completely different from its duplicate, it just so happens that it has a similar or the same answer.
As a result, the OP (and commenters) regularly have a knee-jerk reaction and seem to conclude from the title/body of the linked question that the topic addressed is completely different and this is clearly not a duplicate.
I wonder if, instead, putting the emphasis on the fact that the answer that was provided is good already would help assuage those reactions. Just removing the has been asked before and tidbit should suffice, but we may want to emphasize the answer even more:
This question already has an answer. If the answers of the linked questions do not fully address your question, please ask a new question.