What is Scrum?
Scrum is made of a Scrum Team + Scrum Events that deliver Scrum Artifacts.
The Scrum Team is made of people/roles who attend Scrum Events (i.e. Sprint, Sprint Planning) to create Scrum Artifacts (i.e. a Product Backlog).
There is a funnel effect because if there is no Scrum Team, there will be no Scrum Events, and no Scrum Artifacts will be created.
That's why we focus on the Scrum Team. The People. And this is why Scrum is Human-Centric...and user experience is integral.