Hi @Paul. That’s not a silly question at all. In fact, it’s a topic that has come up a few times already in the community.
I personally don’t like subtasks, firstly because I think they can make a workload look deceptively light. I like being able to see each individual task, rather than have them hidden from view.
Secondly, a subtask doesn’t automatically inherit the parent task’s project, which puts them in a strange limbo.
Finally, and this is the real killer for me at the moment, custom fields can’t be used with subtasks.
That’s just my 2 pence. Check out this thread for many more opinions: