And the thing when it comes to therapy is, a real therapist doesn't have to be prompted and can auto adjust to you without your explicit say so. They're not overly affirming, can stop you from doing things and say no to you. LLMs are the opposite of that.
Also, as a lay person how do i know the right prompts for <llm of the week> to work correctly?
Don't get me wrong, i would love for AI to be on par or better than a real life therapist, but we're not there yet, and i would advise everyone against using AI for therapy.