I think of it as being more of a spectrum where abstractions get introduced as they're needed. The case where one has thousands of lines of imperative code that

I think of it as being more of a spectrum where abstractions get introduced as they're needed. The case where one has thousands of lines of imperative code that is terrible to debug and probably not unit tested is one where the correct abstractions were never introduced at the place and time they were appropriate. Getting this right is almost impossible, that's why we have refactoring practices.