A task manager should have these kinds of basic queries.
Today
Tomorrow
Delayed
Evernote handles:
Stacks = Hierarchy Level
Notebooks = Sublevel of Hierarchy
Notes = Object (Audio, Text, Images, Pdf, Reminders)
The way to manage tasks is to use them as the name of the Project, and the tasks themselves with a title of the action to be carried out.
Each note is a task that can be managed and commented on. Add files, set reminder, and calendar with cronofy. Tag according to state or add the runtime.
This type of administration is used by apps like Todoist, Microsoft's To-Do, Any.do among others.
The advantage of using evernote is that the free version allows very advanced options that other apps do not have.
But its disadvantages are in the edition of notes that are linear system "without format" and the format that can be given will be given by the user. It falls short of Notion.
A very important point to keep in mind is that the objective is to centralize all kinds of tasks in a single application.
Now try if you think this methodology of tasks ...