I once had a Rebbie explain it. He asked that the answer of “Boruch Hashem” in not an answer, because we all know “??? ??????? ?? ???? ?? ?????? ?? ???”, so answering “B”H” is not a real answer. And he explained that in today’s language, the words, “How are you?” or “VOs Macht du?” is not really a question. It is a way of saying, “Hi!” And the correct response to that is “???? ???” also meaning “Hi!”
In todays venacular it is not a question and answer, rather, it is a simple greeting.