Living in the Google ecosystem means a lot of your services are integrated, and that's actually pretty great. Docs knows about email. Email knows about photos. My mobile device knows about all this stuff.
Those ecosystems are not just the software units, they're the integration. And I've done enough decades of running my own bespoke GNU/Linux-derived distros to know that the integration is an extremely nontrivial lift.
There's a reason people keep checking into these software hotels instead of building their own shacks in the woods, even if they don't own the walls. I don't think users will be particularly happy with those who force them to live in the shacks, and the idea that they now own the peeling paint and malfunctioning floorboards will be cold comfort.