The article directly answers your questions, specifically in the “what is GrapheneOS?” section.

For the end user, breaking free from Google means exiting from Google’s services surveillance system wherever possible. It doesn’t mean complete elimination of the use of source code written by Google employees.

GrapheneOS is really the most private option of all viable daily drivable smartphone operating systems available, because your only other options generally involve Apple and Google services dependency.

You can use GrapheneOS and never send any user information to Google, that’s how you “break free.”