If I'm reading you right, you're worried about e.g. some crackpot calling himself a doctor who rubs moonstones on an infection to make the evil spirits go away.

If I'm reading you right, you're worried about e.g. some crackpot calling himself a doctor who rubs moonstones on an infection to make the evil spirits go away. An unfortunate consequence of "anyone can start a medical practice" is that the crackpot would be allowed to operate, but the negative aspects could be mitigated by: * Somebody starting a "Yelp for doctors" * The government could give some approval stamp to doctors using all the existing restrictions, and you could always ask a doctor "Are you XYZ-approved?" It would be a very serious crime for a moonstone-carrying crackpot to lie about his governmental approval, and his status could be verified on a government website. People who solely use government-approved doctors would still benefit, since licensed doctors would still be competing against unlicensed doctors, so there'd be a limit to how much the government policy could distort the market. * People who repair your sidewalk or furnace often advertise "licensed, bonded, and insured". A furnace can burn your house down, which seems a similar risk to medical malpractice. You could ask your doctor if he's licensed by the government, has put his personal capital into a bond, and is insured.