Most frum practitioners do not take any insurance. Lower and middle income households are effectively priced out of decent care. No one is refused quality cancer treatment because of inability to afford it. For some reason, mental health care is treated differently.
It isn't just frum practitioners. Any practitioner with a bit of reputation doesn't take any insurance. If one is lucky, they will have insurance that covers out-of-network (something non-existent in the NY individual market which was created by Obamacare). And even when one has out-of-network benefits, deductibles and co-insurance come into play, as well as UCR (unless the practitioner is experienced enough to bill each session under several codes to get the entire fee covered).
Mental health is also something very hard to evaluate. Is it only the patient (or the patient and their family) and the practitioner? Would it not be more appropriate to have a team of at least two professionals evaluating the care and effectiveness of treatment? Also with psychiatric meds there's always trial and error for the right med (the one that will have the desired effect with minimal side effects which can vary from patient to patient), a ramp-up adjustment period (where initial effect might be adverse) and getting to the right dosage.
I am aware of extreme cases where youngsters are sent to programs that cost tens of thousands of dollars trying to help them.
I don't think this is something that will be solved within our communities (which in a way are better off due to charitable efforts that help in some cases). This is a national (if not global) problem, and needs rethinking of how mental health is made available and managed.