How charmingly naive!
I don't know that people have needed a ruler at many times in history, but there has always been one. A power vacuum almost always results in war, revolution almost always results in war... basically humans like war and leaders. I don't think that will ever go away. We're tribal animals.
Even if people don't need a ruler, leaders will arise, and some of them will recruit violent men to force their will on others, growing into warlords. Factions will fight each other, people will die.
Better, IMHO, to have a codified power structure that seeks to eliminate or at least mitigate these flaws.
I'm not of the faith that says that p2p or crypto currencies are necessarily a good thing. I, personally, think it's a good thing that democratic governments can exert control over fiat currency in order to attempt to mitigate economic disasters. I certainly don't think that the (for example) bitcoin model is a good one.
>> and encrypting their communications
I'm not really sure what this has to do with governments or control. I don't think democratic social order necessarily depends upon being able to surveil everyone, it's just a trap that the current bunch have fallen into.
>> production structure not suffering from possibility of monopolism
I'm not really sure what you mean here either, but it's hard to forsee a state in which monopolies are somehow impossible, or how the lack of them would imply the lack of need for government.
>> how will the government exercise their control?
In much the same way they do now, by the majority of us granting a democratic government a monopoly on the use of force. I'm not sure what bearing the form of currency, or encrypted comms, or even a utopian ideal of monopolistic impossibility have on this.
--edit-- Please do not take this as me saying either that I think the way governments have handled currency is good, or the way they do ... pretty much anything is all totally awesome. Far from it.
--edit 2-- The use of language is interesting here. Correct me if I'm wrong, but you see government as the external imposition of control on to otherwise free citizens? I see it as (at its best) free citizens banding together to achieve collective goals and prevent the worst of human nature overtaking us. The rhetoric and the social measures that come from government in this day and age are pretty abhorrent, but collective defence, roadbuilding, education etc are (to me) vital and useful functions.
"It seems to me that the fastest way to evaluate this idea is to look at how an organization is propelled to statehood in the first place. If incentive structures support states, they will exist."
Since government is the current default, the onus is on you to prove that the incentive structures that select for statehood have changed in a significant way. (Or that they are going to change or could be changed.)
Did you, as an uncoerced free man, ever swear an oath of fealty to the US government? (The pledge of allegiance doesn't count.) Did your parents? Did their parents? Did their parents? Has anyone?
Anybody who may have elected to be governed by the United States is now dead, and the chances are good that you're not even related to them by blood. The vast majority of people who have lived under some form of government in their lives almost certainly did not choose to.
EDIT: Unless they immigrated. Forgot about that option. If you immigrated to the United States, you are exempt from this thought experiment.
But not totally, because you probably weren't stateless when you did.
What about sending his group of followers door to door shooting people who don't acknowledge that he is the leader?