Your comment is full of good and deep analysis and it uncovers a deep flaw in the Copilot: Copilot helps create new code.

All the problems and confusions mentioned above is due to this concrete inherent property of the Copilot.

If Copilot was made to help rearrange [1] existing code to satisfy new or changed needs, there would be no need in such a deep and explanative analysis of yours.

[1] https://www.folklore.org/StoryView.py?story=Negative_2000_Li...

Code is a liability. Less code is less liability. New code is a new liability.

Even tools to create new code is a new and unknown liability, it seems.