Every project I've watched go sideways had the same issue. Somebody says "scope creep," everyone nods, and the room decides to blame the Scrum Master for failing to prevent it, or the Product Owner for changing requirements. We should have pushed back harder. We should have had a change control process. We should have been more disciplined. We need more Agile. We need less Agile.
That's not what happened. In every one of those projects, I couldn't have told you in one sentence what the project was supposed to accomplish. Neither could anyone else in the room. Scope creep isn't a discipline problem. It's what fills the space where a goal should have been.