A teacher or knowledgeable person should answer in a way that fits the questioner's need and level. Excessive jargon may obscure an otherwise helpful answer, while agreeing with an error merely to please the questioner compromises the trust of knowledge.
Example: When a beginner asks about a simple grammar rule, a clear definition, one example, and correction of a likely misunderstanding are more useful than an unrelated technical debate.
نَفَعَ and أَغْنَى are both past-tense verbs. They describe beneficial actions rather than a title or social status alone.