[daok]

Apollo is literally build on top of REST. It adds types and clarify the dependencies between the types. It enhances an existing protocol by adding features.

It is not a silver bullets but it has advantages like self-documenting (Playground), ease of discovery on big API (generated documentation with types) and can have TypeScript type generated for your (reduce the number of interfaces/types to maintain).

Federation is also a good concept if you have many teams that need to converge into a cohesive API gateway.

Overall, if you use it properly it can be a great tool.