It doesn't. That's literally what GraphQL was designed for: To provide a resolver that sits between high latency clients and all of the various REST/RPC services in order to roll up all of the requests at datacenter speeds into one in order to overcome the latency issues.
But you still need all of the various single page REST/RPC endpoints to make use of GraphQL as it is intended. Some developers out there skip the REST/RPC part, making GraphQL their entire service, violating its principles.
If it works it works, but it does not come tradeoff free.