I think it's good to document why things are done, but extracting things out into another function is just documenting what is being done with extra steps. This also comes with a number of problems:

1. Not all languages are readable. Documenting what is being done is important in some C, or when working with some libraries that have confusing usage syntax.
2. Not all people reading the code know the language or libraries well. Those people need guidance to understand what the code is trying to do. Function names can of course do this, but...
3. Not all types can be named in all languages. Some languages have a concept of "opaque types", which explicitly have no name. If parameter and return types must be specified in that language, working around that restriction may result in unnecessarily complicated code.
4. Longer files (the result of having dozens of single-use functions) are less readable. Related logic is now detached into pointers that go all over the file all because of an allergic reaction to code comments, where a simple // or # would have made the code just as readable.
5. Function names can be just as outdated as code comments. Both require upkeep. Speaking from personal experience, I've seen some truly misleading/incorrect function names.