Therapy is entirely built on trust. You can have the best therapist in the world and if you don't trust them then things won't work. Just because of that, an LLM will always be competitive against a therapist. I also think it can do a better job with proper guidelines.
No one should be trusting LLMs, they are wrong too often. Any trust in LLMs is built by the cult of AI and its leaders (Sam Altman etc)