From a workflow perspective, this is basically a practical tickler system (but also integrates notes/collections). Ticklers can be very helpful for removing anxiety about things falling through the cracks, but requires staying in the habit or they become useless. Another once popular system was 43 folders.

imo, the major innovation of GTD and related systems is the inclusion of context beyond do/due dates - specifically the notion of resource availability and alignment towards explicit long-term goals. Done right, this can bring clarity to 'next action' in a way that decreases the incremental cognitive load to select a task to complete - hypothetically making it easier to act in a state of flow and stay in the habit.

Everyone's different, and if any system works for a while thats a win. If you talk to a productivity coach / trainer they will probably share experience that the GTD-type systems have the best impact on busy professionals long-term. When someone figures out how to remove the cognitive overhead of both organization and task selection in a contextual todo-list, I believe its going to change the way many people work.