Is using graphql base on RPC instead of HTTP expectable?

## Background
- I'm trying to use [Apollo Supergraph](https://www.apollographql.com/supergraph) to build the composition of microservices. Its [router](https://www.apollographql.com/docs/router/quickstart) can automatically using defined graphql to communicate with microservices.
- Microservice needs to be fast, we use gRPC protocol for the transport among microservices currently.
- It would be ideal if graphql can run on a RPC server, for it would allow microservices to be fast and have other features Apollo Supergraph provides at the sametime.

## Question
- Is using graphql base on a RPC protocol like gRPC expectable in the future?