Depends ofc on the complexity of the area, but... reading someones code to me feels a bit like being given a 2D picture of a machine, then having to piece together a 3D model in my head from a single 2D photo from one projection of the machine. Then figuring out if the machine will work.
When I write code, the hard part is already done -- the mental model behind the program is already in my head and and I simply dump it to keyboard. (At least for me typing speed has never been relevant as a limiting factor)
But I read code I have to reassemble the mental model "behind" it in my head from the output artifact of the thought processes.
Of course one needs to read code of co-workers and libraries -- but it is more draining, at least for me. Skimming it is fast but reading it thoroughly enough to find bugs by reading requires making the full mental model of the code which takes more mental effort for me at least.
There is a huge difference in how I read code from trusted experienced coworkers and juniors though. AI falls in the latter category.
(AI is still saving me a lot of time. Just saying I agree a lot that writing is easier than reading still.)
Running code in your head is another issue that AI won't solve (yet); we had different people/scientists working on this; the most famous person there being Brett Victor, but also Jonathan Edwards [0] and Chris Granger (lighttable). I find the example in [0] the best; you are sitting there with your very logically weak brain trying to think wtf will this code do while there is a very powerful computer next to you that can tell you. But doesn't. And yet, we are mostly restricted to first think out the code to at least some extent before we can see it in action, same for the AI.
[0] https://vimeo.com/140738254
Don’t run code in your head. Run it in reality and step through it with a debugger.
You mean like a blueprint of a machine? Because that is exactly how machines are usually presented in official documentation. To me the skill of understanding how "2d/code" translates to "3d/program execution" is exactly the skill that sets amateurs apart from pros, saying that, I consider myself an amateur in code and a professional in mechanical design.