[sev]

As @hyperpallium said,

> Rules are a poor substitute for actual thought

There are many times "clean code" is a good goal to have. It depends on what you mean by "clean code" and what you mean by "deduplication". As with many things in software engineering, the best answer to whether you should strive for "clean code" is "it depends."

If you have a utility function that you are redefining in every file, literally copy/pasting it everywhere, then you might as well create a shared function and import it and use it everywhere instead. This is an example of a good goal.