What you are advocating is a return to a supposed "hunter-gatherer" subsistence, albeit with some vestigial technology inherited from the our forebears. Mere survival in societies devolved into fragmented tribalism is no freedom at all, but a condition worse than slavery. What you propose could have been implemented during any era of human social development, since the advent of agriculture. Any one can live-off the meagre produce of a modest-sized lot, but most rational humans prefer to live in civilised society with specialisation and luxuries. Furthermore, not all humans possess the same capabilities, and forcing them into subsistent living by subversion of central authority will result in mass deaths comparable to that of epidemics.

Human technological, social, economic, and cultural advancements only occur within centralised political matrix that provides uniform measure, currency, legal statutes, and sociocultural behavioral expectations. When subjects are displaced due to sociocultural changes from technological advancements, it is the obligation of the crown, or the 'gubermint if you will, to care for the displaced subjects. During the industrial age of the 19th century, when lack of central government control allowed for the regional gentry to appropriate the commons via enclosure, thus displacing the peasantry, the central government's lack of intervention led to atrocious exploitation of the displaced masses. Only via the belated intervention of central authority did the peasants, now "workers," gain a measure of livable wages, rational working hours, and reasonably safe working conditions.

Human misery increases exponentially when central authority is undermined. "Decentralisation" is a rhetoric used by low-born merchant scum to carve out an economic fief, free of political regulations, for the pupose of exploiting the populace. UBI is a necessary political intervention in assisting the displaced subjects during this time of sociocultural change. Ignoring the inevitable social upheaval and rationalising government inaction with empty platitutes of "freedom" and "decentralisation" will only lead to civil strife.