(I think we agree, but it's not absolutely clear from your comment.)

When you ask, "What am I doing X for?", and get back "I want to achieve Y", it often happens that X is far from being an adequate answer to "How can I best achieve Y?", and so must be abandoned. Thus, even after figuring out Y, pursuing the question of "How to best use X for achieving Y?" is a strictly worse option than just "How can I best achieve Y?"