API driven architecture allows for the backend and frontend of the application to be decoupled. This is extremely beneficial in the sense that each end can be built in completely different tools and technologies.
When APIs are the foundation of an architecture, it enables the organisation to scale the app by simply plugging in services as and when needed, instead of having to modify the app itself. This is a great way to plugin and plugout functionality as and when needed without disrupting the original architecture.
As a matter of fact, you could consider this similar to API-as-a-Service.