There is no particular reason both have to be implemented at the same time. Maybe its culturally popular but there's certainly no technical reason.
I live in a former 1st world non-socialized medicine country and I have no option in where I go for medical care other than on a very meta level of which employer I work at and where I live ... in an emergency (heart attack, car accident) the ambulance drives me to the closest ER, there is no free market deciding which is "better". In a non-emergency, my cheap health insurance contracts with precisely one large medical chain in my area, so if I'm willing to do something like medical tourism and fly to another state I could select a new doc, but again no free market ...