The latter raises the question for me: What does it really take for a society to function well? What is the core, what is the essence that is sufficient to enable everyone to live the best possible life?
The answer to this necessitates a high degree of contextual dependence. It depends on what one believes is the purpose of the state, and what they think is a "well functioning society". To answer such a question with certainty, I would argue, is to believe in moral absolutism, rather than moral relativism -- to be completely fair, however, I don't think that I would say that libertarianism is mutually exclusive with moral absolutism, but it does change the framework of the question that you are asking. I would argue that libertarianism, itself doesn't provide exact answers to such questions, but is, instead, a collection of ideals that seek to maximize one's level of freedom under the state. True, it can be said that, for it to be inline with liberalism, it must have, at the bare minimum, an acknowledgement of one's fundamental rights, but I would not go so far as to argue that this is the sole answer to "What is a properly functioning society?", or "What is sufficient to ensure that everyone lives their best possible life?". That being said, the best answer to the latter, I would argue, does seem to be the existence of a competitive free market.