While I admit that logging tasks in Agile results in some overhead, there are many cases where this overhead is worth it. Decomposing user stories into tasks or subtasks in JIRA is a non-special case of task decomposition in general. Here’s an example paper showing that decomposition reduces estimation error.
The magnitude is far from trivial:
The decomposed predictions were, on average, 0 and 8% too low, whereas the predictions of the tasks as a whole were, on average, 13 and 26% too low.