> And you are also less likely to lose track of what windows you have open. I find lots of peoples android phones have like 30 windows open - this is a fault of its interface.

There is no need to keep track of them or close them, since the app lifecycle is managed automatically by the system – having a window (called activity on Android) open doesn't mean that the app is running.

Non-foreground activities are automatically suspended by the system and resumed when you return to them. Processes with suspended activites are automacially killed when resources run low.