I don't get what's so user-hostile about Android. Everything negative about the ecosystem is mostly Google Play and the legacy of every OEM forking Android for the better part of a decade. Sure, file pickers are inconsistent, filesystem is chaotic but it's performing quite well on most hardware, runs on phones, TVs, laptops, tablets and mini PCs and AOSP doesn't contain any hooks for Google to siphon off data. GrapheneOS isn't so much undoing evil Google stuff but extending upon their work and improving memory protection and adds security features that can be easily toggled based on assumed threat models of the user.

Google's ownership of Android is definitely headed towards user hostility though, I'm not arguing against that. But just the source that GrapheneOS is based off of doesn't contain too much stuff that shouldn't be there, to my knowledge.