The models are beyond expert level in many areas at this point.
Do you really believe that adding extra junk to your prompt is going to make the model write code better than it does already?
Again, imagine going to Terrence Tao and "prompting" him to get better at Maths, do you think you can do it? What prompt would you give to him to make him produce better maths. Unless you're already a world-leading Mathematician I think you would find it hard.
Extra prompt text isn’t to make the model smarter, it’s to pull attention towards what you want. “Do code review” is far different from “Make sure changes align with existing architecture” or “follow these enterprise standards XYZ”. The model just acts as an average of its training data, which may or may not align with your goals.
It's not that the models aren't smart or whatever; we know they're extremely capable.
There's always going to be value in being able to clearly communicate what you want the model to do, especially when the context is lacking.