Critical path in Agile Projects?

This is a question I had in my mind for some time. How do we tackle the critical path in agile project? do we really have a critical path in Agile? or is it implied by another element of Agile? I think the answer is this. This was explained by one of my mentors and I think it clears out lot of doubts I had in my mind.

Lets talk about traditional project management triangle. See below.

 

In traditional context we know what the scope and the budget is and the challenge is to deliver. We then workout a plan and draw the network of the work to be done. Since the time is the driving force we determine the critical path. It is basically we are hunting for a project deadline than trying to reshape the scope and cost. Therefore critical path plays a major role in traditional project management. 

In the other hand, when it comes to Agile, our time is fixed. That is an iteration. Within a fixed iteration what is the amount of work that can be taken? So the scope becomes the variable element and cost and the time becomes fixed. Therefore we hunt to achieve a piece of scope and more often we reshape the scope time to time. As a result of this nature there is no need of a critical path as the driving force is not time but scope.

This is not to tell which is better. Whether to select traditional project management or Agile is context depended. Also, I would say there is a critical path inside an iteration but not in the context of formal critical path but when it comes to dependent user stories or sequential completions then there is kind of a critical path inside an iteration.

So critical path is not applicable to Agile. It is like talking about Tax in communist world(conceptual). Tax is there to make the wealth distributed in a society and when it comes to communism tax distribution is not applied as wealth is already distributed by the framework itself.