When viewing a subtask in my list, it is helpful to know the task to which it relates. Asana, for example, does this. This snip shows how it looks: https://snipboard.io/Q5nrBx.jpg
You see the tasks and just to the right of it, you see the parent in light gray.

Being able to see the parent gives an instant reminder of WHY we are doing that subtask and adds clarity in case the wording of the subtasks is a little fuzzy.

Yes, on the desktop version, if my window is expanded so the right-hand pane is visible, I can click on any ONE subtask and see the name of the parent task. But I cannot scan the list and see at a glance the subtask and its parent side-by-side.