It's time to fork it
Forking Android is not an option. Android is way too complex for any company or band of open-source developers to take up. The fork would quickly fall behind Google's implementation and become effectively useless.
Even the big guns like Amazon can't afford keeping up with Google's speed.
I wouldn't be surprised if Samsung or Xiaomi eventually forked to make their own "developed in the open" Android.
Though given how little those companies have respected their users so far, I feel like this is a bit of a monkey's paw.