The alternative to Google doing it, would be your browser fetching every single page, reading the meta tag, retrieving the XML, parsing it and then displaying t

The alternative to Google doing it, would be your browser fetching every single page, reading the meta tag, retrieving the XML, parsing it and then displaying the contained title tag. Without trying Firefox, I can pretty safely say that's not happening in the milliseconds that it takes for Google to get me my results and my browser to render them fully.