The Scrum Guide has up to ten appearances between «collaborate, collaboration, collaborative …». It is not casual or redundant. It is very important.
The rules of the game that Scrum explains, the definition of roles and responsibilities, are not to have an argument with which to accuse one another when things go wrong, depending on what he says each one has to do. If a Scrum team comes to absorb what it really is to be an agile and high performance team, everything ends up being a collaborative effort.
It is not «this is our business, do not get involved» or «this is my decision and not yours» because it is put in the Scrum Guide. That is only a rigid first step.
The taking of responsibility and the division of work areas are a matter of those: responsibility and focus. When both are so clear that they are not questioned because they are already natural, it is understood that this allows everyone to do their part of the effort, the pieces fit together and the work flows as what it should be: collaborative.
Each one understands and does his / her best so that everyone can do the same.