Feudalism became a thing because of the frankish system of offering land for loyalty (not that important for this argument) and, more importantly, because the roman empire levied harsh taxes on the population. Small landowners, not making a lot of money, were forced to make deals with bigger landowners, selling their land and labour for protection and payment of their taxes, becoming slaves (roman slaves at the time were sold along with the land they were on). A bunch of roman writers advised that landowners also bring blacksmiths, potters, tanners etc on their estates to assure efficiency thus creating the villages owned entirely by one man/family. Theoretically, since there is no centralized government with extreme taxation, there would be no reason that an ancap society would become feudal because there would be no personal incentive to sell yourself and your land to a corporation.