I think it's a bit of two-edged sword. Low-quality therapists are part of the equation (i.e., insurers paying for IFS, infinite supportive therapy, SE, and other sham treatments) that have made insurers rightly wary of psychological services. Notice that one person was testing for ADHD who did eventually get paid (insurers around here would've flatly denied that claim). That said, the process of reimbursement is way too opaque and bureaucratic to make it worth it for many providers. The low reimbursements only add insult to injury especially when therapists can't bill them for administrative costs.
I'm not sure what the answer is. It seems the social contract should be that if a psychologist brings their best, the company responds in kind with timely payments that reflect one's expertise and the cost of living. There was a major insurer around here that was losing tons of money on mental health that did not have a UM process in place. When they instituted one, tons of therapists (especially mids) freaked out on the local listservs. A friend of mine working at UM at said company told me the process is mostly meant to screen out so-called 'bad therapy'. which they defined as not adhering to evidence-based practice. How that's defined and enforced, I have no idea.