By default PostGraphQL gives you basic create, update, and delete mutations to offer complete CRUD functionality. However, sometimes it may be useful to disable these default mutations and only use custom Postgres procedures to mutate your data.
If you only ever use custom procedures you may not run into as many naming conflicts and you can restrict mutations that can be made by the client.
Of course individual default mutations will still be disabled if no user can use them given the Postgres grant system.