Going fast means to go even faster. While being just fast isn't pleasing Google, the case is not always like that.
It was a fundamental shift to Google Search when it developed 'Instant ' The feature introduced in 2010 under the leadership of Marissa Mayer. She called this change a "fundamental shift in search", and Google marketed it as "Search before your type". as Google uses its prediction to figure out what users are likely to type.
Instant works when users were entering search queries. At one point they see a dropdown that comes from the query box for quick suggestion, and down below, the search engine result page also keeps on searching and changing as users are typing.
The feature boasts real-time search, optimized to show results instantly based on a per-letter query.
Users using Instant can save a lot of time while searching on the search engine, while at the same time improving experience.
For Google, speed is one of its priority, and it always has been. This is why Instant was introduced. But when things go beyond the matter of speed, there is also user satisfaction, and also trends. Somehow, when these things change, Google's perspective also changes. And after about 7 years running, Google is killing the feature altogether.
The thing about Instant is that Google continues to provide search suggestions as users are typing, but won't actually load any final search results until users select one of those suggestions, or press the enter button.
While Instant was one of the most unique features of the search engine, it isn't popular or intuitive as it was meant to be. Users don't really use or need it.
According to Google:
What Google is saying is that, mobile searches are dominating. And Instant never really make much sense for mobile users. Trends have change. Google had a good portion of the search market on desktop back in those years, but as the trend shifted and the company sees mobile users using Search more frequently, Instant would just clutter the experience.
With Instant eliminated users will only see search suggestions and then be able to click on those suggestions to see the results. The search results won't not load any result pages without clicking on a search suggestion or clicking enter.