Google is not optimized to be the best search engine in the world; it is optimized to be the best tool for transforming the currency of intention into shareholder value. This means that its search capabilities only have to be good enough to keep you coming back to Google for search. Considering that Google’s only real competition is Bing, the bar is not very high.
This does leave Google in a unique position. It can subjugate search to advertising efficacy. In other words, Google can optimize for maximum revenue – which is exactly what it does.
Search results on Google are fast, but are they really what you are looking for? If Google revenue was derived directly from search, it would be the best search engine on earth. But Google doesn’t make money from search; it makes money by getting you to click on ads (which you would never need to see if search results gave you exactly what you were searching for). Oh, and if Google were optimized for search (as opposed to advertising revenue), it would go out of business (or have to charge a subscription fee).
Said differently, search is just the best clickbait Google can produce.