Insurance cos can still compete on the merits of their networks and, in theory but sadly I think not in practice, these schemes could work in favor of the patients if the insurance company uses their network to balance cost with service quality.
A very dominant one could effectively rule a region as a cartel, though.
The answer is on some of the other comments on this page. Insurance companies make reimbursement so difficult that some doctors do not want to accept the insurance.
As many other comments point out, insurance companies pull many tricks to try to not reimburse.
I've submitted claims directly to insurance before and had the same issue.
- Your claim gets rejected for missing information, but they dont tell you what is missing
- Your claim gets rejected for being a duplicate, but the previous claim also got rejected, or both got rejected
- Your claim is "not received" there is no record of a claim
- Your re-submitted claim gets rejected because 90 days have passed, but of course, it is because you were forced to resubmit over and over
Lobbyists