Very good point and the rest of the world is definitely benefiting from our R&D while paying lower prices for the same medications we pay more for. Also us having the finest medical treatment in the world now benefits those in other countries stuck with socialized medicine, the ones who can afford to travel here for care do so in many cases and that benefit will disappear.
And where ill we travel when we have socialized our own medicine? For a time modern medicine will be available offshore. Even now the best English doctors are practicing modern medicine in Thailand and India. Well and good for those who can jump on airplanes- until the antibiotics run out. Then the elite will be in the same boat with the rest of us. Replacing a knee will no longer be advisable because the chance of dying from infection will be very high.