Any organization that designs a system (defined more broadly here than just information systems) will inevitably produce a design whose structure is a copy of the organization’s communication structure.
As Wikipedia points out, “Conway’s law was not intended as a joke .. but as a valid sociological observation. It is a consequence of the fact that two software modules A and B cannot interface correctly with each other unless the people who made A communicate with the people who made B. Thus the interface structure of a software system necessarily will show a congruence with the social structure of the organization that produced it.”