Is the backend of a mobile application mainly BFF?

BFF (Backend For Frontend) is a pattern where a separate backend is created for each client type (e.g., mobile application), optimized for its needs. In mobile applications, BFF is often used to aggregate data from different services and provide a convenient API.

In my experience, the backend of a mobile application was often built as a BFF, acting as an intermediary between the mobile client and microservices. This allowed optimizing traffic, reducing the number of requests from the client, and centralizing authorization and data aggregation logic.