It's only not absurd if you believe violence is a legit method to claim to ownership land. If I had some kind of alien technology that allowed me to subdue a particular region by force, would you consider it a legit nation? All current nations are the results of various conquests, subsequent stalemates, power struggles, etc. Then a bunch of politicians/military/etc claim the right to control everything in that geographical area. Mafias have the same policy. They claim the right to control businesses and extort people in a particular area, whether or not the people there agree.

Nations' rulers claim some sort of 'collective' land ownership of very large geographical areas, as if everyone owned it, yet these rulers are usually the only ones that have rights to decide what happens to the land. There are various property rights structures, with more or less consistency, but ultimately these individuals can violate these rules, because after all, it is maintained by violence, not by consent.

The only model that could possible be consistent and voluntary, would be something akin to the homesteading principle at small community levels, where individuals or groups can claim the use of small areas of unclaimed land, or trade/buy land from others. If there were many thousands of such communities, people can opt in to whichever community they find and participate voluntarily in the land use, or opt out to some other place. A suppose this is sort of like anarchism but with community governance.