Re: yeah but what about the jobs...?
> a post-scarcity condition where every demand can be instantly met at no cost.
That only works for material things. As a society we all place great value on intangible things: time, choice, security, freedom, health (including a pleasant environment), knowledge and entertainment and some higher human functions such as recognition and respect. These cannot be manufactured and in some cases require the collaboration of those around us to achieve. Just as soon as one person's needs become dependent on the actions of another, you immediately find yourself back in a trade/barter situation where "what's in it for me" kicks in and you find you have to give up something you have in order to obtain something you value more.
That immediately brings cost back into the game.