As @NobbZ said, GraphQL is not ideal when it comes to caching, especially not with HTTP caching.
A CDN would have to cache POST requests (already a no-go in HTTP, as they are meant for side effects). Also, the benefit of caching the whole query would be limited, as the clients could make slight changes to the query, or request fresh data alongside the cached one, and the whole query will be a cache miss.
There are some approaches to caching partial results server-side, but nothing coming close to the well-established and simple HTTP caching, used by CDNs.
I personally like the flexibility and control over data that GraphQL gives to the client, but when caching is important I use REST. For example, we have REST endpoints for a few high-traffic, cacheable resources, alongside the GraphQL API that serves most of the other needs of the client.
One other possibility worth mentioning is to have a GraphQL API on top of REST endpoints. The GraphQL API would act as the client for the REST endpoint, and would have to take care of caching using HTTP headers.
