GMail and Google Maps were also both ruthlessly incremental. They seemed like big improvements over what had come before because they had incubated inside the Googleplex for a couple years before they were released, and because the competition hadn't improved in nearly a decade.

It's more that Search was a non-incremental leap forwards, and that Google was basically the only company of the dot-com era that had attempted an ambitious technological goal and succeeded. Google Search really was fundamentally different from previous technologies; its main rival Alta Vista, for example, ran on a single box and used very standard text-ranking techniques, while Google thought very much out-of-the-box in terms of ranking, scale, and architecture.

Google X is very much a Larry & Sergey project, and Larry (while Eric was CEO) was often very critical of how incremental employee projects were and how they weren't taking enough risks on fundamentally different approaches.