I believe that bearing costs is the reason why a person prefers one country over another. Good medical care will not be free, and then you may not be able to afford it, especially for individuals in the middle and poor classes. There are also consequences after the operation, such as care in the first months, medicines and other costs.

Also, some countries are better in certain disciplines, this chart may give you better information, although I am surprised at the reason for choosing Mexico, perhaps because of the flight costs)