A task is a function of a story. What is important is the achievement of the intent or desired outcome of the story and NOT the checked checkbox of each task when it is completed.
We can check the checkbox of all tasks in the story and still miss the intent of the story.
Therefore, the focus must be on the achievement of the intent.
However, tasking is handy for other purposes: to understand the story better; to help estimate the story…
Tasking is really optional.