The major reason why the Internet is expanding rapidly and continuously is because Google wants it to be like that as they can make more money if the Internet is bigger. And the way they encourage the Internet to grow so rapidly is because their search engine penalises websites that do not constantly add fresh pages.
If you leave a website alone for several months it will basically die because Google's search engine will stop finding it or find it less often. Conversely, if you constantly add to a website with fresh pages Google's search engine likes it and it will tend to find the site more often. It will rank the pages higher in search results. The more pages you can add the better the search results will be provided the content is good. It's pretty much as simple as that.
So Google dictates the Internet. They manage it and what they want they get. If they want an expanding Internet they can manage that through their search engine as described. This is not a criticism of Google. If anything it is praising Google because it is probably a good thing that it does expand as by and large the Internet is beneficial to people.
It is interesting, though, to speculate how things could have been different. If Google's search engine rewarded sites which had been dormant for a year by ranking them at the top of the search results, Internet expansion would come to a grinding halt quite quickly. The whole complexion of the Internet, of how we live, and such phenomenon as social media online would have been entirely different if Google had set up their search engine differently. It's a thought worth bearing in mind because it is at the foundation of how we use the Internet. And that greatly affects our lives.