How did "taskwarrior" become so influential? It doesn't seem to provide anything other GTD code doesn't provide, but it only offers an inaccessible interface. What's the draw here?
Some people want a minimalist tool that they can read a manual for and then configure / install extensions for to their liking, and some people want a discoverable batteries-included GUI.
taskwarrior is simply the program and format that has the most support and biggest extension ecosystem for that first group of people.
Both are fine.