I think that the field of game theory, and as the most simplistic example, the prisoner's dilemma, shows that libertarianism, as defined by the idea that individuals acting in their own self-interest will create the greatest common benefit, is flawed. Specifically, this will limit the benefit of each individual as well as the aggregate.
Individuals acting in their own self-interests categorically do not arrive at optimal solutions for themselves or for the whole society. It's a complete joke, mathematically provable, and thus ridiculous that it's still being argued. We need coordinators. All forms of government have been imperfect at achieving perfect coordination, which has inspired libertarians and objectivists and etc., but that doesn't invalidate the coordinators' work. Instead, a meaningful endeavor would be to improve the scientific rigor and quality of the policy-based coordination. This is what my research as an undergraduate was based around...
Libertarian, I invite you to go start an investment bank and act in your own unfettered best interest. I'd be hard pressed to see you not end up in a similar situation to investors in any of the past bubbles and collapses.