Given that people are generally bad at giving accurate estimates, the story points is asking the question in a different way, it's asking "what's the likely complexity of implementing this?" rather than "how long would it take to implement this?", because people are likely to be too optimistic on the time estimate, and more likely to be accurate on the complexity estimate.

It is a multi-step estimating process to arrive at more accurate estimates:

1. estimate complexity via story points, filter out features that will be implemented according to the "complexity budget" 2. break the features down into sub-tasks 3. estimate the time it takes to do each task