I agree it's not always cut and dry which module to use, or whether to use a module for something extremely simple (which is why I mentioned it being more than a few lines, which should weed out stuff like left-pad I would hope), but I think knowing there is a module and it's suggesting it might be a good first step.

The only thing worse than using a module that has a bug/security problem for a function that's just a few lines and not used again in the codebase is when the content of that function is copied in place instead of being included and nobody has an easy way of knowing whether that's the code that was suggested and included in their project. Worst of both worlds.