This question is directed to those who claim that it is impossible to achieve a stateless society. Let's suppose that, for whatever reason, the majority of humanity will always believe the lie that governments have legitimate authority and should be obeyed. To begin, even if this was the case (which I don't agree with and will explain why later), no one can confidently make such an argument using evidence, because the future is unpredictable and uncontrollable. Unless you have a crystal ball and can look into the future up until existence stops existing, there is no way to be 100% certain of everything, including what humans will understand and believe later on. Centuries ago, people took it on faith that kings had the "Divine Right" to rule their subjects because God gave them the authority to do so. Now, the few kings that remain have had their roles constrained mostly to ceremonial ones without much political power, if any. In addition, this argument that having a stateless society will never happen doesn't actually address or rebut the fact that governments are illegitimate.
Even assuming that the belief in government will always be around (which, again, I don't agree with), here is where my question comes in: which world would you rather live in? Would you rather live in a world where most people understand that using violence outside of self-defense is wrong, that everyone has equal rights and own themselves, and that the concept of authority is illegitimate because people have the right to disobey immoral commands? Or would you rather live in a world where most people believe that wars are justified, and that attacking innocent people is okay and should even be committed if it is done in the name of the law? Are you okay with most of the world believing forever that words written down and made "law" by random politicians are more important than justice and morality? Does evil and injustice all of a sudden become acceptable simply because they will always occur?
Unfortunately, it is true that evil will always exist. You can't prevent everyone from murdering, stealing, attacking and so on. However, is this a good reason to be apathetic and not try to stop murders and thefts at all? Imagine how that sounds in the following context: "Well yeah, he just got robbed, but who cares? You can't do anything about it. Someone somewhere will always get robbed at some point!" Should we just stop teaching children that attacking and stealing from others is wrong altogether? Hardly.
Since it is logically and morally impossible to refute voluntaryism, people who desperately want to hang on to the irrational belief that governments are legitimate resort to the weak excuses that no society has ever been truly voluntary because 1) it can't happen due to human nature, and that 2) apparently, every "attempt" at it has "failed". To tackle the first point: it is not "human nature" to want to obey others. As children, most of us instinctively resist and rebel against having to obey our parents; people we normally love and have a bond with. Considering this, it is absurd to suggest that humans naturally want to obey politicians or others with power; people they hardly know at all in the vast majority of cases. One of the main reasons the idea of government is still implemented is because people have been taught to fear imagining a world without it, not because they have an inclination to be submissive followers. True human nature is a desire for freedom to be able to experience life to the fullest.
As for the second point: anarchy has never existed in the way that voluntaryists like myself envision it, because humanity has never grasped, and still doesn't grasp, the principles of self-ownership and non-aggression fully. If it did, societies wouldn't have established states, since the people would have recognized them for what they are: ruling classes that violate both these principles by asserting the right to do so because they wield "authority". Therefore, voluntaryism has failed no more than the abolition of slavery did when slavery was supported by many.
If everyone who opposed large-scale injustice decided it was easier to shut up and do nothing instead because it's hard to make a difference, there would be no force for progress towards justice, peace and freedom. Those who did fight against evil and oppression didn't know if they would succeed, and they didn't know of any potential consequences they would face as a result. Yet they fought for their values and vision anyways, because, as the famous saying goes: "The only thing necessary for the triumph of evil is that good men should do nothing."
This is why, as a voluntaryist, I will never stop arguing that the idea of government is currently the primary obstacle to true peace, justice and morality. What I care about is the truth and justice, not whether I will see a stateless and voluntary society in my lifetime. It would obviously be terrific if I was able to witness a mass evolution of human consciousness where people cared and thought about these issues enough to realize that engaging in politics is counterproductive to achieving any good for society, but this is less important to me than actually laying the foundation for this to happen sometime in the future, even if I'm not alive by then. I'm not saying a voluntary society won't come about in our lifetimes, but it requires dedication and effort for it to become a reality in the first place. Good luck, fellow voluntaryists!