I have known and worked with many, many engineers across a wide range of skill levels. Not a single one has ever said or implied this, and in not one case have I ever found it to be true, least of all in my own case.
I don't think it's humanly possible to read and understand code faster than you can write and understand it to the same degree of depth. The brain just doesn't work that way. We learn by doing.
The same goes with shell scripting.
But more importantly you don’t have to understand code to the same degree and depth. When I read code I understand what the code is doing and if it looks correct. I’m not going over other design decisions or implementation strategies (unless they’re obvious). If I did that then I’d agree. Id also stop doing code reviews and just write everything myself.
I also haven't found any benefit in aiming for smaller or larger PRs. The aggregare efficiency seems to even out because smaller PRs are easier to weed through but they are not less likely to be trash.
It’s interesting some folks can use them to build functioning systems and others can’t get a PR out of them.
This will only be resolved out there in the real world. If AI turns a bad developer, or even a non-developer, into somebody that can replace a good developer, the workplace will transform extremely quickly.
So I'll wait for the world to prove me wrong but my expectation, and observation so far, is that AI multiplies the "productivity" of the worst sort of developer: the ones that think they are factory workers who produce a product called "code". I expect that to increase, not decrease, the value of the best sort of developer: the ones who spend the week thinking, then on Friday write 100 lines of code, delete 2000 and leave a system that solves more problems than it did the week before.
It is 100% a function of what you are trying to build, what language and libraries you are building it in, and how sensitive that thing is to factors like performance and getting the architecture just right. I've experienced building functioning systems with hardly any intervention, and repeatedly failing to get code that even compiles after over an hour of effort. There exists small, but popular, subset of programming tasks where gen AI excels, and a massive tail of tasks where it is much less useful.
This might be the defining line for Gen AI - people who can read code faster will find it useful and those that write faster then they can read won’t use it.