Probably varies by state on how worth it is is, but psychiatrists are sued for wrongful death (either when patient kills themselves or someone else or deaths in restraints/seclusion etc), wrongful diagnosis, failure to diagnose, failure to hospitalize, abandonment, violating confidentiality, failure to warn/protect, failure to provide informed consent, harm from medications, failure to supervise mid-levels, and boundary violations.
But yes, because the standard of care is low in psychiatry, it is quite hard to be successfully sued. psychiatrists account for about 1% of NPDB malpractice reports, but 4% of physicians. The annual risk of lawsuit for psychiatrists is 2.5% which is significantly lower than physicians in general. Working in ER, inpatient, and correctional settings has higher risk of lawsuits.