GraphQL was designed to solve facebooks issue - efficiently fetch data for an entire view. In addition to this it provides structure that makes it easier for large dev teams to collaborate. If your app is similar to facebook from a technical perspective just jump right in. If you are very different, definitely do some more exploration first. For example I spoke to a dev on the facebook ad analytics team and he complained that he couldn't find a good way to fit their queries into the GraphQL paradigm. Their queries are much more dynamic than most consumer/business apps and includes advanced aggregations etc.
You/he seem to to say "GraphQL is not as flexible as SQL", and that is true but it's not in competition with SQL (but REST).
Answering with a question, can that facebook dev fit the same query in rest somehow better then in GraphQL. Any any other way besides "i'll build this new endpoint for this new query"?
