Why would you so willingly give up what are intended to be company secrets like that?
Google could hand you the source code, and you still wouldn't be able to implement what they have and compete against them.
Execution is more important than almost anything else.
Occasionally you need to cough up a really clever idea. Those days are really rare, though.
Google has put a lot of money and effort to make their system nice. Working in a mono repo without that much effort is very frustrating, doubly so because there's nothing individual teams can do about it. It's especially worse if you can't even make team specific branches on the mono repo to try and isolate yourself from the steady stream of breaking changes elsewhere.
However if you're a team lucky enough to get out and do most things on your own git repo, then you're now the only ones responsible for making that better or worse. Fortunately there's a ton of open source to learn from and use, so taking control of your own team's destiny to get to a point better than before doesn't have to mean much work.
Sure there is. They can architect code in a way that it doesn't break heavily when other people do things. IE abstract things reasonably. They can test things well. and they can complain when other teams aren't doing either and it's making them less effective.