The managers will tell you the economy of every fort teeters on the brink of collapse and is held up only by a robust supply chain and a carefully considered and continually adjusted array of work orders. Should the manager's vigil lapse for a moment, the fortress will plunge into chaotic ruin for the grim amusement of Armok. Just ask Armok and they'll tell you the same.
There is no such god as Armok, so all managers are obviously insane.
We might instead ask the scholars. They will begin with some chatter of "supply and demand" which is not immediately offensive. The people demand beer and wine and any proper holding must supply it, we understand this. But from here the scholars begin to speak of arcane concepts. Global trade. Extraction. Appraisal. "Commodity" and "value" and where value allegedly comes from. They will even suggest that the "value" of all objects in the fortress could potentially be expressed in terms of those tiny metal discs that have no use except as chaff for automated training rooms.
At this point it is clear the scholars make up this nonsense as they go, and we must walk out of the library at speed.
In the barracks they will tell you, of course, that it is soldiers who drive the dwarven economy. Soldiers who march on distant towns to bring back dozens of those scrolls the scholars like so much. Soldiers who ensure nearby villages do not miss their annual tribute of buckets and mismatched socks. Soldiers who fight giant olms in the dark so our butchers and tanners can keep their jobs. Soldiers who pry perfectly good steel weapons and salvageable steel armor from various goblins, which can outfit more soldiers.
This makes a certain grim material sense, but doesn't seem scalable. Soldiers are mostly observed standing around or hitting each other.
Let us at last consult the bards. The bards will tell you plainly that the whole of the dwarven economy is driven by loitering in the tavern. And true enough, most tasks in a fortress seem to bend back toward keeping the tavern stocked, giving dwarves things to wear to the tavern, keeping the tavern safe, nursing dwarves until they are healthy enough to go back to the tavern, and so forth. No holding has ever been observed to suffer ill effects from too much loitering in the tavern. Even the scholars will confirm that going outside the tavern has a shockingly high correlation with violent death.
And as bards walk the whole face of the world from tavern to tavern, and speak to all they find at each, like as not it will be their theory that sticks.