[G1N]

Of course not. While some development acceleration might be expected, at best you'll get some multiple that is representative of the overall quality and experience of the devs you work with.

Copilot has definitely helped me speed up via not having to type a lot of boilerplate and line completion, but I'd say that would be at most ~50% speed up when it comes to greenfield development and half that when it comes to maintenance work (and even these figures are probably generous). A 4x speed up sounds ridiculous; expectations like this are how your codebases get filled with GPT generated garbage that is connected together with GPT generated glue and then wrapped with GPT duct tape and a bow

[AnimalMuppet]

Amdahl's Law comes to mind. It can't speed up all the parts of the task, so there's a limit to how much it can speed up the whole.