Sure, and there are systems that work to prevent or those people from practicing. Imperfect systems, to be sure, but at least I as a citizen can look up the training and practice standards for therapists in my state, and I have some recourse if I encounter a bad therapist.
What safety systems exist to catch bad AI therapists? At this point, the only such systems (at least that I'm aware of) are built by the AI companies themselves.
Surely they're vastly outnumbered by A) legitimate therapists; and B) the sheer number of people carrying around their own personal sycophants in their pockets.