Control and Focus; those are the two most critical skills for interviewers and interviewees.
Recruiters need to control the conversation. If you ask them why they left their last company and a dissertation on the nature of supply chain management follows, stop them, shut them up, and get them to answer the question you asked. This is very common, interviewees rarely answer the question they were asked, they almost always answer the one they expected and for which they rehearsed the answer. Recruiters need to have the balls to stop them and redirect them to the needed information.
If you are a candidate, there is one piece of invaluable evidence that will help you immeasurably: ATFQ. It stands for: Answer The Fucking Question. Pay attention to what you were asked and answer it, answer it directly and succinctly, and do not hive off into unnecessary details or explanations of marginally related topics. If you need a moment to think, that’s fine. As an interviewer I would rather received a considered answer in 30-60 seconds than a haphazard line of BS instantly.
And remember, hold your interviewer to the same standard. If their answers are obviously bullshit, I’d personally call them on it. That’s a judgement call, of course, but if you don’t absolutely need a job it’s important to break yourself out of the psychology that says you have to get this job. Most people, when they interview, are to intent on trying to get the job to actually take a moment to learn about the job. Or, more to the point, to learn from the behavior of the recruiter and manager in front of them how things actually work at the company in question.
Observe and learn when you’re in an interview. It’s what the person interviewing you is doing, when it comes time to accept or reject an offer you will be at a disadvantage if you spend the interview trying to please them and never finding out what it is you need to know to inform your decision.