Does GraphQL have a way to disable features? If so, it seems the sane way to go about implementing it for a set of data would be to enable the bare minimum features, and enable anything needed specifically after reviewing and researching what it allowed and how it interacted with other other features. If you can't, that seems like a very dangerous tool to use.
By default, no features are implemented in GraphQL. It’s a protocol like SQL or REST.
You can adhere to the protocol, and doing so gains you an ecosystem of tools to use, but you have to actually build the nitty gritty bits yourself.
Think of it this way: you can create a graphql schema for a calculator then implement it. It will do math, but store no data and definitely have nothing to do with a relational database.