> they need search to drive users to the ads
Why? The websites we visit can still be infested with google's ads, and so can our gmail accounts, and so can the youtube videos we watch, and they can push ads directly onto our cell phones 24/7. Google has plenty of ways to force ads into your life.
Google used to need search in order to build extensive dossiers on everyone. It told them what people were looking for online. What they were interested in. Now Google has their cell phones, their browser, and their DNS servers doing that for them. Most people are handing all of their browsing history to Google. Google doesn't need search, which is why it's been allowed to atrophy into uselessness.