You're not wrong, but at the same time I think it's a decent data point that getting it right is not straight-forward and that, practical speaking, you at the very least need to think very carefully before actually using it.
"The idea of it" is sometimes fine, but then there's also "the practicality of it", and sometimes that's a very different thing.
Remember the old microkernel vs. monolithic debate; everyone more or less agrees that in principle, a microkernel is better. But the practicality of it is a lot more complex, so monolithic kernels and hybrid ones are much more common. Microservices vs monolithic is essentially the same debate, and I've seen a lot of Microservices with very poor implementations and a lot of problems. That doesn't mean the idea is bad in itself, but if it's hard to execute well, then you do need to be very careful.
There's tons more examples of this. You also see this sort of thing in e.g. politics, where what's "more fair" vs. "what's actually achievable without introducing heaps of bureaucracy and overhead" are sometimes very different things.
In the case of GraphQL, I think it's pretty obvious that the general idea, as described from a high level, is a good one. But the practicalities of it are a lot less straight-forward, as this article explains reasonably well IMHO.
