If there is no chance of failure there is no sense in returning a status. This makes only sense, if the code that uses the function would actually evaluate the returned status code and respond to it with some error message or some way to correct an error. Too many useless status codes and programmers using it will form a habit of ignoring them.
Though depending on the actual functionality it may be relevant to keep that option for changes you may want to make in a future version of some library. (But then you should know what you are doing)
It can be questioned if the status code approach is a good idea anyway. I prefer exceptions for error handling, since they make the code more readable.
In some languages (and many use cases) you need the return value for other purposes. Either to simply return the result of a function or to return something like
this as you do when overloading certain operators in C++. So making it a principle to return a status wont work anyway.