I have been an Apple fanboy for 10 years and their recent abysmal software quality and complete lack of the 'final touch' they've been known for made me go back to Linux and Android. Because there I can at list fix those annoying bugs myself — or at the very least, I can have them reported publicly for visibility.
I went from an advocate to 'fuck that shit' in 6 months, and if I recall it was one annoying bug too many that was the tipping point. I have a feeling many people share a similar experience roughly at the same time. And I actually think same thing is happening with Windows. So why not Android, too?
So yeah, I think companies can absolutely inadvertently reach a tipping point with one of those seemingly benign decisions.
There's simply no reason for AOSP to matter to google because AOSP doesn't matter to any serious manufacturer.
Everything at Google is going downhill due to cost cutting, not specifically this. It's more of a neutral thing for GrapheneOS than a bad thing since it presents a lot of opportunities too. Google is likely to lose control of Android via antitrust action but whether that ends up better for open source is an open question.