Where I'm working the star developers don't have a great culture of being conscientious about writing code their non-star colleagues can read and modify without too much trouble. (In fairness, I've worked exactly one place where that wasn't the case, and that was only because avoiding this problem was a personal vendetta for the CTO.)
We gave them Copilot and it only compounded the problem. They started churning out code that's damn near unreadable at a furious pace. And that pushed the productivity of the people who are responsible for supporting and maintaining their code down toward zero.
If you're only looking at how quickly people clear tickets, it looks like Copilot was an amazing productivity boost. But that's not a full accounting of the situation. A perspective that values teamwork and sustainability over army-of-one heroism and instant gratification can easily lead to the opposite conclusion.