Yep. Some efficiency gain is surely possible with "intelligent" autocomplete (i.e. codex instead of intellisense), but it must be code you wanted to write.
"If you think you're paying me for typing code, maybe you should have hired a typist and not a programmer?"
I think Refactoring will be hardest but Maintenance, Structuring and Domain it's all that even current Codex is good at.
I think with current generation of algos we can get to very good google searches but ones that you can throw own documents/code at. Later probably also DB schema etc.
Code is not a goal. It's a tool. The tool can get better. But it will always be a tool and someone has to control the tool.
Writing code is super easy. It's the easiest part of our job.
The hard part of our jobs is to understand why we need to write code and right along that, what we write code for ?
Maintenance Structuring Domain knowledge Refactoring
Those are hard things to do. And they are not solved by having a program writing code for you.