Not easy in any absolute sense, but very much easier in a relative sense. You're right that Google still have indirect levers to pull, to mess with independent

Not easy in any absolute sense, but very much easier in a relative sense. You're right that Google still have indirect levers to pull, to mess with independent email providers, but the distance is more and the scale is less. In comparison, Google is literally an absolute gatekeeper on Android (insofar as Google Play is the only app store that the mass market cares about, the mass market would never accept an AOSP repackage without Google Play Services, etc.), and Chrome has become the reference implementation for web standards (insofar as some increasingly large proportion of developers develop against and only ever test in Chrome).