Because such code is dumb, tedious and joyless. I have to bite my lip sometimes to convince myself writing them is not a waste of time, because people demand it, but I hate it to my core.
Copilot is that unfortunate boy that has to do all that manual work. It is the ultimate code boilerplate mixer.
It is not going to write all code for you, if you goal is to have it THINK for your then you are due to disappointment. But it would be able to help you be a more efficient and slightly happier programmer.