In my experience, couples therapy is an absolute waste of time. However, it can serve a few purposes. The therapist we went to actually called him out on his circular conversation and abusive language. This was very validating to me!
However, some therapists don’t fully understand narcissism or don’t have personal experience with it. They can be easily fooled and swayed to the narc’s side.
Another advantage it offered for me was that I was able to say that I even tried therapy with him. There were no other options left to explore, and I filed for divorce. I knew therapy would not work, but I did give it an honest try. In the session, I was painfully honest with him, trying to find the right words to help him to see. I had even asked the therapist to help me to explain it in a fair and honest way. It was never going to work though. My husband just twisted everything all up and turned it all back on me, like he always did.