Cultivator sects on Haishan need a source of food and other resources, so they inevitably form synergistic relationships with mortal villages throughout the island. Just about every cultivator on the island is tied to one of its four major factions, so the tithe paid to the various villages' divine protectors is partially meant for the faction to which that divine protector works. Silver Pine Village, for example, pays a 10% tithe to Wei Da, and about half of the value he receives from the villagers is sent back to Shigong Temple.
Mortals outside of the major sects and clans typically perform low-level but necessary labor like farming, mining, or transportation. Once these goods reach the land under direct control of the faction, the faction's outer disciples handle second-tier labor that must be handled on the property like cooking, cleaning, security, picking sacred herbs, and infusing ki into objects.
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All of this is handled autonomously by the outer elders and the divine protectors scattered throughout the island, and things have functioned this way for tens of thousands of years. This system is in place for the sole purpose that a handful of inner disciples can focus every moment of their lives on cultivation and the various activities obliquely related to self-advancement. Whenever a three-hundred-year-old master ascends to the fourth realm, there are tens of thousands of unseen laborers who toiled in silence to pave the way.