your exams and cleanings, then get a discounted fee on the work that needs to be done. No 3rd party to deal with. You know exactly what you will owe before treatment is done. And it is much less headache for the office to deal with the insurance company games.

Your complaint is about insurance companies, not the offices that do their best to estimate what insurance will pay. That is constantly changing and sometimes treatment is denied for stupid reasons. They don't make their big profits by paying claims.