Having worked in big tech and small startups, I think GraphQL is a brilliant way to solve an organizational problem that massive tech companies have.
It's that the team maintaining the API is different from the team that needs changes to the API. Due to the scale of the organization the latter doesn't have the access or know-how to easily add fields to that API themselves, so they have to wait for the maintainers to add the work to their roadmap and get back to it in a few quarters. Relevant Krazam: https://www.youtube.com/watch?v=y8OnoxKotPQ
At a small start-up, if the GET /foo/:fooId/bar/ endpoint is missing a field baz you need, you can usually just add it yourself and move on.
It's that the team maintaining the API is different from the team that needs changes to the API. Due to the scale of the organization the latter doesn't have the access or know-how to easily add fields to that API themselves, so they have to wait for the maintainers to add the work to their roadmap and get back to it in a few quarters. Relevant Krazam: https://www.youtube.com/watch?v=y8OnoxKotPQ
At a small start-up, if the GET /foo/:fooId/bar/ endpoint is missing a field baz you need, you can usually just add it yourself and move on.