In terms of difficulty, writing code is maybe on average a two out of ten.
On average, maintaining code you wrote recently is probably a three out of ten in terms of difficulty, and maintaining code somebody else wrote or code from a long time ago probably rises to around a five out of ten.
Debugging misbehaving code is probably a seven out of ten or higher.
GitHub Copilot is optimising the part of the process that was already the easiest, and makes the other parts harder because it moves you from the “I wrote this” path to the “somebody else wrote this” path.
Even during the initial write, it changes the writing process from programming (which is easy) to understanding somebody else’s code to ensure that it’s right before accepting the suggestion (which is much less easy). I just don’t understand how this is a net time/energy savings?
At the end of the day is all about trust. Do you trust code you find in SO/Copilot to be good enough for your use case?
In my case I do not trust SO code. Whenever I use SO, if I find some snippet that seems to be the code solution I'm looking for, I copy-paste the snippet on my IDE, read through it carefully, rename variable names as needed, handle edge cases, remove unused code, etc., etc. Any code solution I find in SO gives me the "starting" kick, which is about 10% of the total effort of writing code from scratch. The remaining 90% (to understand the code that is being committed) cannot simply go away. I do not expect Copilot will make much of a difference.