It seems to me that the libertarian/anarcho-whatever ideology hinges on a couple of key ideas. The most important in my view is that every individual has inherent rights to security, self-determination and property (unless of course that individual violates the rights of others).
I want you to consider a scenario: Imagine that every individual had the means to protect themselves from any physical attack, kidnapping and therefore coercion. This seems, in theory, to be the ideal for a libertarian. No one would be able to harm you and you also could harm no other individual; no violent crime of any nature could occur.

However, consider for a moment what that would mean for property. There would be no physical means to preventing theft, and property would only be able to exist as an agreement (Don't steal any of my shit and I won't steal yours). Would this reduce property to a theoretical idea that would not actually exist in practice?