A focus on decoupling helps keep any system more manageable, agile, maintainable, flexible, adaptable.
When a system is not decoupled, one component affects another. This results in cases where both components require change.
The main components in a vehicle are decoupled. You can fix or change the steering without having to worry about the exhaust component.
In an organization, oftentimes systems and processes are highly coupled. Meaning if you change one system that creates effects in other systems. This increases the complexity and makes change more difficult.
As a business analyst is we are always trying to minimize how couple systems are, we are increasing value for the client.
This pertains to all levels. If data can be decoupled from the applications by having a strong database design, data can be easily moved between applications. If UI components are separated from application components, the UI can be changed without having to replace the entire application.
The same perspective pertains to processes and roles. If a process or a role has little influence from other processes or roles, change can be made easily. If not, the change can ripple throughout the entire organization.
Taking the time to reduce coupling pays large dividends over time.