There's no chance LLMs have a sufficient training set of effective therapists-patient interactions, because those are private. Ergo, there is no need to wait, it's DOA. Anything else is feeding into LLM hype. It's that simple.
"people have reported positive experiences with chatbots for mental health support. In an earlier study, researchers from King's College and Harvard Medical School interviewed 19 participants who used generative AI chatbots for mental health and found reports of high engagement and positive impacts, including improved relationships and healing from trauma"
And that is about the present, not even what may come in the future. Not all therapy is life and death, and there are already signs that it's a good thing, at least in some limited domains.