[beders]

It is still a bit shocking to see how many people are not getting the distinction between an API and a RESTful service.

They are very different things and they have very different goals. The hint is in: how much do you value the client?

If you have full control over both client/server or if we don't care about any 3rd party developing a client library for your service, then go with something like GraphQL or gRPC or SOAP with a nice, typed spec you can generate your code from and optimize the heck out of the bytes coming through the tubes.

If OTOH you have an interest to create a RESTful service that is discoverable, that doesn't require constant client changes, that offer a wider variety of resource representations, that need to stand the test of time, then use HATEOAS and a RESTful architectural style.

gRPC is yet another ... RPC. Nothing good or bad about that. Just make sure you understand the consequences.