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?
Open source encourages contributions so that it grows beyond the initial start: https://en.m.wikipedia.org/wiki/Open_source
Also, I remember when Android came out and needed to find its place among all of the custom operating systems. Making it open source so that everyone (including other manufacturers) could make it their own was a huge selling point.