I also wanted to understand why GQL was getting so much attention in a REST vs GraphQL way so I implemented a GQL microservice that had the same features as a service that I had implemented previously as REST. Both services ran on node.js and connected to the same data stores, etc. I ran both services on the same load test lab and documented my findings at https://glennengstrand.info/software/architecture/microservi...

The TL;DR of that blog is this. There isn't much value that GQL can provide over REST + OpenAPI. GQL is still in its infancy so APM is easier with REST. The biggest argument for GQL is returning the right amount of data but GQL is slightly slower than REST because the server is having to parse what is essentially a mini program with every request.