The providers (hospitals, clinics, labs, doctor practices), insurers/payers (whether for profit like United, nonprofit like most Blue Cross Blue Shields, or government like Medicare), and pharmaceutical/medical device companies fight each other the whole time to make the most money off of the patients/beneficiaries/taxpayers. Big Pharma runs up prices and persuades doctors to prescribe their treatments, while doctors themselves have a profit motive in running up unnecessary treatments, all while insurers try not to pay for stuff, necessary or not.
It's a broken system, but it's also worth pointing out that the scammers in each camp hate the other camps just as much as the public does. There are hospital execs and pharma execs basically cheering on the anger at insurers, who will turn around and rip off the same victims in a different way.