The major medical problems that you "don't have a choice" but to get are not 100% of all medical problems that can exist. There are only so many organs available for transplant every year (thousands yes, but no millions) but seeing the doctor for the sniffles is bounded only by the number of people in the US, 300 million. There's a difference between something that will kill you in short order (like a horrible car accident where you're bleeding out) where you take whatever medical care you can get at any price, and the more mundane, routine stuff like ACL surgery where you can afford the time to shop around or perhaps even forego it entirely.