It might work for a band of hunter-gatherers, but people are not wired to live in the massive groups we do today without regulation compelling co-operation and good behavior. We're not altruistic enough. We're too tribal, anti-social and self-serving; too willing to exploit others for our own gain or to act in such a way as to harm the interests of others.
A libertarian society means no public education, no public fire or police services, no pollution regulations or food inspection services, no Medicare, Medicaid, 'food stamps' or any public safety nets, no national parks, no building codes, nothing ensuring the safety and effectiveness of drugs, &c, &c, &c.
With everything privatized, nothing gets done that someone can't make a buck on, and what services do get organized will cut whatever corners they can to minimize costs and maximize profits. Moreover, you won't get such money losers as rural mail delivery or electrification.
Even
with regulations, we get Enrons, Bernie Madoffs, predatory pharmaceutical companies, industry ignoring safety and pollution regs to save a buck, &c.
With no regulation or oversight and everyone out for themselves, I'm afraid we'd get a predatory, 'wild West' society of wolves and sheep.
The linked Libertarian Platform is nicely crafted to sound hopeful and avoid calling attention to the full picture and its ramifications.
David Koch learned this lesson back in 1980, when he ran for vice president as a Libertarian, but made the mistake of coming out with a clear outline of what libertarianism involved.
That didn't work out well at all.
The unvarnished 1980 platform:
David Koch 1980 Libertarian Party Platform - look familiar? - Democratic Underground