Well, this is not a problem at all - long before you ever need to ask "who will buy stuff" the world will burn. That will fix the problem & whoever rises to po

Well, this is not a problem at all - long before you ever need to ask "who will buy stuff" the world will burn. That will fix the problem & whoever rises to power from the ashes will be hopefully more careful than their predecessors - maintain social stability and not radicalize big parts of the society against you.