I'm convinced at this point that GraphQL only works effectively at a small scale, where inefficient queries aren't disastrously slow/heavy, OR at a large enough scale where you can dedicate at least an entire team of engineers to constantly tackle performance issues, caching, etc.

To me it also makes no sense at startups, which don't generally have such a high wall between frontend and backend engineering. I've seen it used at two startups, and both spent way more time on dealing with GraphQL BS than it would have taken to either ask another team to do query updates or just learn to write SQL. Indeed, at $CURRENT_JOB the engineering team for a product using GraphQL actively pushed for moving away from it and to server-side rendering with Svelte and normal knex-based SQL queries, despite the fact that none of them were backend engineers by trade. The GraphQL was just too difficult to reason about from a performance perspective.