More people should try high performance services with non-traditional protobuf implementations. The fact that every language has a generated parser in no way preclude you from parsing them yourself. Hand-rolled serialization of your outbound messages can also be really fast, and the C++ gRPC stack will just accept preformatted messages and put them on the wire. Finally the existence of gRPC itself should not make you feel constrained against implementing the entire protocol yourself. It’s just HTTP/2 with conventional headers.