If you simply want to be a "therapist," I don't think there is one.
However, because the Psy.D is a doctoral degree, it opens up many other possible career doors/avenues because it can provide one with experience in specialty areas (behavioral med consultation, neuopsychology), assessment and diagnostics issues (capacity and fitness for duty evaluations), as well as roles such mental health education/outreach, training, administration, prorgam evaluation, and clinical research. If you have no interest in any of these things and simply want to be a therapist, then yes, I think that the Psy.D is probably overkill. However, there are many who argue that masters-level providers should be restricted to conducting time limited, supportive psychotherapy only.