GraphQL debates become a bit motte and bailey.

Yes you can change anything you like and add in any behaviours you wish. But, each time you do that you move away from the promise that "you basically don't need backenders" or "if you're finding it tough, just use this tool!" The latter of which has appeared in this comment thread already more than once.

You can technically accomplish many things with GraphQL. But the effort to do so erodes the benefits promised.