Google hasn’t made any real profit on anything besides advertising during its whole existence. It’s much less diversified than Microsoft, Apple, or Amazon.
Second, and I think perhaps more fundamentally, Google is incredibly well diversified among ad channels, so I think lumping that all together and then drawing the conclusion "Google is at risk because they get all their money from ads" misses the mark. Google has AdWords, AdSense, DoubleClick, YouTube, Android, GMail, Google Assistant/Nest, etc. They may be dependent on ads but they control a staggering breadth of ad channels.
86% of their revenue is still ad based, YouTube is widely thought just to be break even and I specifically said profit not revenue. How much of thier profit is ad based and how many of thier other ventures are losing money?
Second, and I think perhaps more fundamentally, Google is incredibly well diversified among ad channels, so I think lumping that all together and then drawing the conclusion "Google is at risk because they get all their money from ads" misses the mark. Google has AdWords, AdSense, DoubleClick, YouTube, Android, GMail, Google Assistant/Nest, etc. They may be dependent on ads but they control a staggering breadth of ad channels.