A guest should not have to know which bar sells which thing. Routing is the venue's problem, not theirs.
A guest looks at a venue and sees one place. They want a drink and a plate of something, and they do not care that the drink comes from a bar run by one team and the plate from a kitchen run by another.
The venue sees the opposite: separate stock, separate staff, separate tills, often separate businesses underneath one roof. Historically the guest has been made to learn that map — queue here for this, over there for that.
If every item knows which counter makes it, the guest can order anything from one menu and each counter receives only its own lines. One order, two tickets, two collection points, and nobody at the counter has to read past things that are not theirs.
The practical gain is at the counter, not on the phone. A bar that only ever sees drink lines works faster than a bar reading a full order and mentally filtering it.
One piece of setup, done once: every item on the menu is assigned to the station that makes it. Venues usually find this harder than they expect, not because the software is fussy but because two counters both think they own the same item and nobody has had to settle it before.
It is worth settling. An item with two owners is an order that arrives twice or not at all.
At the edges of the night. Nobody needs routing when one counter is open; everybody needs it when five are open and three of them are busy at the same moment. That is the load a venue should set up for, because it is the load that generates the complaints.