In 2001 Google probably only sold search ads.
Today they sell ads on so many digital places, some of those they own.
As for the question of "long term" - Google X was founded only 9 years ago.
That probably a reasonable time for a drug startup to show sucsess.
And they recently started testing self-driving cars with no safety driver , with real passengers. So they're close to some deployment.
That seems quite good.
Microsoft has released Azure.
Saying that a Google sells ads in more places is about as “diversified” as saying Apple sells iPhones on more carriers.
YouTube profits from selling ads, that's true.
Yes YouTube makes all of their money from selling ads. But it's fate is highly independent from Google search. That's diversification.
Same idea goes for Other Google businesses.
As for Apple - it's less diversified than it seems: the fate of the watch, for example, is highly dependent on the fate of the iPhone.