What is the purpose of defaults in Apollo Link State?

Question

Why would one do this:

const clientState = {
  defaults: {
    networkStatus: {
      __typename: 'NetworkStatus',
      id: 1,
      isConnected: false,
    },
  },
  resolvers: {},
};

Over this:

const clientState = {
  resolvers: {
    Query: {
      networkStatus: () => ({
        __typename: 'NetworkStatus',
        id: 1,
        isConnected: false,
      }),
    },
  },
};

The advantages I can see of the latter approach are:

• It's more akin to writing resolvers on the server
• It supports async by simply returning a promise
• It acts as a default because, from my current understanding, the resolver is only called on a cache miss.

I can't see any advantages to using the former defaults API, but I'm sure there's a reason otherwise it wouldn't exist?