People die eventually no matter the medical investment, so theoretical demand is infinite. No amount of money (aka fraction of total productivity) thrown at the

People die eventually no matter the medical investment, so theoretical demand is infinite. No amount of money (aka fraction of total productivity) thrown at the problem will be enough in terms of that adding more money would not make someone, somewhere live years, weeks, days or at least minutes longer. Effective demand is a compromise between money and death and people just happen to be very, very uncomfortable talking about that.