They are experts at talking to people, not knowing what people should do.
When people find out I’m a psychotherapist, many of them like to ask me questions.
“I’m afraid of the dark. Is it normal that I sleep with a nightlight?”
“My boyfriend doesn’t share his emotions. Should I break up with him?”
“I hate my job. Should I quit and go back to school?”
“My partner and I don’t have sex as much as we used to. How many times a week should we be ‘doing it’?”

It makes sense that I get asked such questions. After all, psychotherapists are often assumed to be experts on what is normal and appropriate behavior. A quick look at the self-help shelf of your local bookstore only confirms this. It’s chock full of books authored by preening experts who seem to know precisely what your problem is and exactly what you should do about it. Listen to them and you’ll supposedly discover the secret to living the good life.
But this doesn’t fit with my experience as a therapist. Over the years, I’ve learned that I usually don’t know what’s best for my clients. Regardless of the problem at hand—whether to divorce, change jobs, confront people who have offended or hurt them, etc.—being licensed as a psychologist doesn’t provide me special knowledge about what clients should do. Further, I don’t think other licensed professionals know what clients should do either, even though some of them pretend otherwise.

There you have it. I admit it. I don’t know whether you should sleep with a nightlight, quit your job and go back to school, or break up with your partner. I have no inside information about what constitutes the “good life.” I say this because I’ve worked with enough clients to know that these sorts of questions have different answers for different people. Put simply, I’m not an expert on what you should or shouldn’t be doing in your life.
This doesn’t mean I don’t think I’m an expert at all. It’s just that I believe people are confused about what kind of expertise psychotherapists have—including many psychotherapists.
What is the expertise of a psychotherapist? It’s quite simple (although hard to do well). Good psychotherapists are adept at productively talking to people about their life problems.

I may not know if you should quit your job, but I do have a lot of training in being able to fruitfully talk to you about it. I may not have a clear notion of how much sex will satisfy you and your partner, but I am pretty good at facilitating the sensitive conversations necessary for you to answer such questions for yourselves.

In other words, too often therapists represent their expertise incorrectly. We’re not experts at what clients should do when faced with particular life challenges. We’re experts at helping clients talk things through and figure out solutions for themselves. Put another way, we’re experts at interpersonal communication. When most effective, good therapists engage in productive and helpful conversations that disrupt the status quo and encourage clients to entertain new possibilities.

So, should you quit your job and go back to school? I honestly don’t know. But I’d be happy to sit down with you and talk about it. That’s because I’m an expert—not at knowing what you ought to do, but at talking to you about your difficulties and helping you generate solutions.

https://www.psychologytoday.com/blog/making-meaning/201709/what-kind-expert-is-psychotherapist