Regarding potential gains, Android has all but cemented its position as the smartphone OS. Microsoft did the same in 1995 with Windows in the desktop market and it has 90%+ marketshare there, 23 years later. It's very likely it will still dominate the desktop market in 2045.

Android will be at least a loss leader for Google for decades to come. And they made $10 billion in profit in 2017 alone (of course not all of it is driven by Android, but you get an impression of the scale).