But good code reviews are much harder at scale than building good code in the first place. The reason we write code _and_ do code reviews is because doing both

But good code reviews are much harder at scale than building good code in the first place. The reason we write code _and_ do code reviews is because doing both is better than doing either. But copilot isn't even equivalent to a code review: code review is not only checking for correctness. It's also asking questions and helping the author walk through their solution by having them reconsider it. Copilot doesn't ask questions, nor can it answer them or provide a rationale.