GrapheneOS on Nostr: SailfishOS is already largely closed source for the code specific to it and would be ...

SailfishOS is already largely closed source for the code specific to it and would be a far worse starting point than hard forking AOSP even if it wasn't. There are a lot of stakeholders in open source AOSP and it would be able to continue without Google. The fact that they haven't closed it is why it hasn't been split away by a group of organizations working on it together. Multiple organizations have made hard forks with varying degrees of success but there wasn't much reason to do it.