Imagine you have 5 meetings with different people. For each meeting you have a separate meeting notes page. In each such page you hand out tasks (in context) to people .
One week later, if you want to make sure those tasks are actually getting done you would have to check all those 5 pages and check the status of those tasks. Imagine you responsible for making sure tasks are actually get done in many different spaces with hundreds of pages.
If there is a macro which can grab all the task list from different space and page into a single page, managing different single task list such as those in the meeting notes will be much easier.