A lot of the rest of the reasons are carrying the deadweight of administering regulation, and dancing with the existing and prospective malpractice suits that randomly benefit the system sometimes, but always cost everybody, and warp the practice of medicine and patient healthcare experiences.
So what's the solution? Some states have already limited malpractice liability but that hasn't done much to hold down costs. When patients are harmed by preventable medical errors they should be compensated.