According to the Android cofounder, Bill Gates is responsible for the "biggest mistake of all time" that cost Microsoft $400 billion

Bill Gates said Microsoft’s biggest mistake was not betting on Android early enough.

That delay let Google seize the mobile OS market, while Windows Phone arrived too late.

Android’s cofounder replied that the goal was to keep Microsoft from controlling phones like PCs.

Steve Ballmer blamed Microsoft’s mobile failure on arrogance and overconfidence.