Testability for one, but I would also argue that those functions are there for using. If some block of logic is sufficient to stand on its own, it should. I’m not saying do it arbitrarily, but it’s been my experience that small functions lead to more readable code and better testing. Most people write a 15 line function treating it as if it does a single thing when in reality it’s doing two or three discrete operations

Well named functions, called in succession increase readability, not decrease.