Is that 99% of software all the same? Like, have you really not observed huge differences in the readability of the code you encountered? Have you not found tha

Is that 99% of software all the same? Like, have you really not observed huge differences in the readability of the code you encountered? Have you not found that sometimes it is painful (or close to impossible) to extend or build more features on top of a particular system, while other times it is quite straightforward, even a joy? If your answer to these questions is yes, to what do you attribute the difference? How would you counsel a young software engineer or team? How can we write better, more maintainable software that still allows us to deliver features quickly?