Productivity matters because it increases our agency. Agency is our individual capacity for intentional action.
Some might want to maximize their efficiency so that they can be better at working and making money. For me, it is larger than that. It's about how can I be of actual benefit to the world in my life. And productivity tools like Getting Things Done, habits stacking and personal knowledge management are tools for amplifying my ability to serve others, which is something I'm dedicated to.
As we grow in our ability to do the things we want to do, we increase our agency to do the things we want to see in the world.