Search isn't a Google product anymore, it's a learning tool like reCaptcha. Sure, the ads at the top of your search results are a product, but the real value of search is that they can capture everything you do to learn more about you. So every time you refine your search and try again, they learn a little bit more about what you're interested in, or what you're doing, and maybe what you're working on for your job, and advertisers will throw money at them to get the "better" information for targeting. Search is just the latest casualty of the war for your attention online.