I think you will agree that over the last few years, content was being created at an incredibly rapid pace. This is how Google succeeded in the market; massive amounts of content were being created, and it was their job to index it all. At one point, Eric Schmidt, former CEO of Google, said as much content was being created every 2 days as had been created from the beginning of time to 2003.
Today, though, I would assert that Google is failing because search is becoming irrelevant. Searching for stuff across such a large data set means you're always going to find something because the very act of searching means that you have a preconceived notion of what you want to look for!
However, by using Topic Discovery, you can zero in on what your customers actually care about rather than searching blindly for what you think they care about. That's a huge difference.
For example, you may discover that customers are creating content around one distinct set of topics. You, as a brand, may think you know what those topics are based on history, but in fact they are constantly changing. The challenge, then, is to constantly refresh what you know about the trends that matter to your customers based on their current actions - that is, the content they create - instead of searching endlessly for trends you think matter to them.