I often feel the same way. I've seen cases where trying to add functionality to an existing but "very clean and correct" codebase ended up being extremely diffi

I often feel the same way. I've seen cases where trying to add functionality to an existing but "very clean and correct" codebase ended up being extremely difficult and the result felt far too complex in my mind. I've come to think the real sin is coupling. If you try to keep your codebase clean at all times but don't refractor often enough, you end up with coupling where it shouldn't be, which can sometimes be a lot worse than some of the so called "deadly sins" such as code duplication.