over population isn't a myth, its a serious problem like Leprosy or the Black plague, but just because it's a serious problem doesn't mean there's only one final solution. Around 2-4 million people are born in the United States every year. It stands to reason that deaths should roughly match these figures, and it is known that the world record for elderly isn't passing the 120 year mark. Somewhere in this mess we can determine - and the same applies to every country - whether it is worth forcing life extension laws and options upon the general populous. When birth rates are extremely low, obviously you want the society to be as safe and healthy as possible, but when birth rates are high, in the middle of a high population and lower resources, it doesn't make sense to try to keep everyone living to the age of 100+. When we choose to fight disease, cancer, drunk driving, war, or domestic violence and murder, we have to take into consideration two basic facts:
#1, everyone is going to die eventually
#2 sometimes (not always) a higher population in a country with limited resources can be detrimental to itself and future generations
Responses in terms of logistics have largely been through centralized authorities, but I've found individual responses are much better at checking the populous. Even Socrates opposed unwanted life extension measures that have become a hallmark of modern society. We glorify how many tubes and drugs it takes to keep our vegetative elders alive in a tortured state and manifest that sacrifice with enormous medical bills and destroyed families.