I don’t understand why Google didn’t just made Android closed source. They would’ve made custom roms impossible and therefore more able to control and spy on it’s users. Why did Google made Android open source, while Microsoft’s Windows is still closed source to this day?
Even though Android has lots of open source code in it, many core components are actually proprietary. Just look at the state of Replicant, and you’ll see how much can actually be done with just the FOSS parts. It’s not really daily driver material just yet.