I mean it's kinda true. But they still had to figure out that these were the projects/companies worth buying and afterwards pursuing and advancing them such that they would become the cash-cows they are today.
IMHO the Google Home devices and Chromecast are quite successful.
I admit these are probably not powerhouses on the level of Android, Chrome or YouTube. However it's just not possible to create a powerhouse every 1 or 2 years.