GitHub only has 240 employees. Google has around 50,000. Bad comparison. It's like saying "Ruby on Rails works for GitHub; if they can do it, why can't Google use Ruby on Rails?"
If you read any of their articles on how they make remote work for them, they do it by and organizing the entire company around remote work, IIRC. And they still have offices.
And projects don't talk to each other? And departments don't talk to each other? And departments don't report to inter-department leads/heads? There aren't Director or VP level managers?
If only there were some sort of text and voice based communications methods we could use to facilitate the transfer of information between disparate groups...