The example in the article is too short and incomplete to be meaningful. In a real program there would be something that does actual work for "tasks" and "payme

The example in the article is too short and incomplete to be meaningful. In a real program there would be something that does actual work for "tasks" and "payments" and deals with errors, providing context for technical decisions instead of forcing the choice of minimum complexity (i.e. two plain functions instead of a class) as the only applicable design guideline.