I think they are overselling Google's contributions a bit. It was more "Web 2.0" that shook Microsoft's dominance in tech. Google was a big curator and pushed state-of-the-art. Google was built on a large network of commodity hardware, they were able to do that because of the Open Source Software. Microsoft licensing would have been prohibitive to such innovation. There was some reenforcement that helped Linux gain momentum in other domains like Mobile and Desktop. Googled helped curate "Web 2.0" with developments / acquisitions like Maps and Gmail. When more of your life was spent on the web, the operating system meant less and that's also why Apple was able to make strides with their platforms. People weren't giving up as much when they switched to Mac as they would have previously.

Microsoft was previously the gatekeeper to almost every interaction with software (roughly 1992 - 2002). I don't know of good books on it but Tim O'Reilly wrote quite a bit about Web 2.0.