For algorithms, this might indeed be different. Not only are algorithms usually small and very focussed snippets, the emphasis is on performance and hence mutab

For algorithms, this might indeed be different. Not only are algorithms usually small and very focussed snippets, the emphasis is on performance and hence mutability, language primitives and shortcuts are common. I can definitely see that languages like python or go beat pure functional languages in that regard. For business logic and glue code (which in my field is the vast amount of code) I think it is the opposite though.