"In Scrum, the entire Scrum Team (Product Owner, Development Team and Scrum Master) is responsible for the success of the Sprint, their project. Let me show you how that works."

It _doesn't_ work.

The result is no accountability. That's why organizations that _claim_ to use Scrum actually _do_ have development managers who are accountable.

What Scrum gets wrong is the idea that no one is individually accountable, or has any individual authority. What is needed is someone who leads well - not autocratically, but with a Socratic style.

Leadership cannot be removed from the equation. Saying that "everyone leads" is not an answer - it is an escape clause. There is no substitute for good leadership. Look at SpaceX for example, or Amazon. Those organizations have leadership.