The author goes on to explain a few scenarios where the pattern is helpful. It's not to keep main.go as small as possible, it's so that you can test parts of your main.go file properly. In my experience, if all of my logic is stuffed into `func main() {}`, then I can't actually test it. If I have a helper method(like run in this case), I can test out specific scenarios and ensure the application handles it properly. Some of the examples Mat gave were handling context cancellations properly.