Although it's possible that shipping ESM code via the "module" field of
package.json may have reduced the size of these packages, the primary
reason for the very large reduction in package sizes is that we're no
longer bundling in the dependencies, so the new sizes reflect just the
packages themselves.

Including dependencies in per-package size measurements is misleading
because most apps use multiple apollo-link-* packages, so shared
dependencies will be included only once in the bundle, and thus should not
be counted as part of each individual package's size.

Fundamentally, measuring bundle size on a per-package basis doesn't make a
whole lot of sense. Instead, we should use an example application that
uses a typical/representative set of Apollo packages, and bundles
everything together using a modern bundling tool.