The request is useful. It is just not the whole story.
One of the easiest ways to create unnecessary work is to treat a stakeholder's first solution idea as a finished requirement. The request tells you what the person currently believes will help. Discovery tells you why they believe it, what evidence exists, and what else might work.
That distinction became increasingly important as my role moved from development into client-facing project management. A developer can be excellent at building the requested feature. A BA or consultant also has to ask whether the requested feature is the right response to the problem.
A simple conversation pattern
That sequence does not challenge the client. It shows respect for the request while making the decision better informed.
The practical benefit
Once the problem is clear, scope becomes easier. You can explain why a feature matters, which parts are essential, what can wait, and which alternatives deserve consideration.
The goal of discovery is not to prove the client wrong. It is to make the problem precise enough that the team can make a good decision.