When I am in a nested subtask that has 0 subtasks underneath it, I find it not obvious that it itself is a subtask and there is a parent task above it, which might have other subtasks that you don't want to forget about. The breadcrumb at the top is too small, and I feel like I want it in the sidebar with the "0 subtasks" words. I think this would be beneficial to essentially say, "yes, there are no subtasks to this subtask, but don't forget there is a parent task, and that might have other subtasks". Essentially, when you are in a subtask, it's easy to forget there might be other subtasks within the parent task, because it says "0 subtasks". It would also be beneficial if you could navigate to the parent task from the sidebar without leaving the current subtask. Currently, you are stuck in that subtask unless you click the breadcrumb at the top of the task, but it feels like I should be able to navigate the subtask sidebar from there, find the parent task, and go to it without leaving the current subtask first. All of the above mean it's easy to forget that there is a parent task with other possible subtasks.
