Fair point about the DB scaling but not sure if everyone is going to run into this issue. Also, lots of solutions are emerging for this specific problem (with different trade-offs of course) like distributed databases (crunchy, YugaByte, Spanner, etc.). Most folks I work with get by with a reasonably sized DB and some read replicas.
Not a GraphQL problem though IMO.
Seeing some feedback on GraphQL - Hasura has had support for converting templated GraphQL into RESTish endpoints (with Open API Spec docs if needed). We are planning to do the same for this streaming API as well - does anyone have good examples of existing REST/RESTish endpoints that something similar?