Except they purchased their way into many of these.
Their advertising business was built on a number of acquisitions (DoubleClick, AdMob) - strategic acquisitions, surely, and they improved on them since - but it is not as if they bult the business from the ground up. The same goes for video streaming (YouTube - after attempting to create their own), and mobile OS (Android).
With Android in particular it can be argued that it would not be what it is today without them, but they also heavily leveraged their other services to promote and maintain control over Android.
Their advertising business was built on a number of acquisitions (DoubleClick, AdMob) - strategic acquisitions, surely, and they improved on them since - but it is not as if they bult the business from the ground up. The same goes for video streaming (YouTube - after attempting to create their own), and mobile OS (Android).
With Android in particular it can be argued that it would not be what it is today without them, but they also heavily leveraged their other services to promote and maintain control over Android.