The difference between building an operating system and building a web scale search engine is that the former is mostly just work and there is a lot of material

The difference between building an operating system and building a web scale search engine is that the former is mostly just work and there is a lot of material to learn from in order to inform that work. Sure, it requires talent, skill and perseverance, but there is a shitload of operating systems you can study. It also doesn't require tons of hardware, nuclear-reactor-scale power and enough bandwidth to rapidly copy, and keep updated, a significant portion of the web. Sure, just making an OS doesn't mean it takes over the world. But guess what: you have the same problem with search engines.