A few years ago, the internet was a lot simpler.
Information was to be found on websites, for the most part. Shure, 
some obscure ftp and telnet sites, some chat channels, and a lot of newsgroups.
Google just had to crawl usenet plus the http space, index all the information it found, and make sure users found what they wanted. Google did an amazing job here, and was rewarded by stellar growth, incredible user loyalty, and thanks to its superbly implemented way of auctioning off ad slots, a massive income stream.
Today, the internet is a lot more complicated. Information is often stored in Apps. Some of them are web apps, some aren’t. Some of the Apps’ content is searchable for Google, a lot isn’t.
And here is where it becomes difficult for Google: Why would a company make its App searchable, just so that Google could display more relevant search results, and as a return sell ads better.
Content providers not only get no share from ad sales, but actually have to pay, if they want an ad to link to their content.
Right now this paradigmt becomes questionable. Google’s search results are only as good as the amount of content they can access. Would you use a search engine that only had access to every second page?
Google has to start sharing some revenue with App devs if they want to have access to their content.
App developers do not rely on Google for the promotion of their apps. Here App stores have become the main channel. And this weakens Googles biggest strength as a gateway to traffic and users.
This becomes increasingly pressing as the Internet transforms from a very homogenous WWW to a polymorphic interconnection of Apps, Channels, Websites and streams of data.
Maybe its time for a new competitor in the search field. A disruption, to further abuse this horribly strained word. A company that builds its paradigms in the present form of the internet, Maybe even a collective effort. The ‘Net would be better of for it.