Agile is not about "mean efficiency", this is a serious and widespread misunderstanding.
Agile is a risk management method.
You won't build things faster with agile in general. It's aim is to decrease the chances of spending 80 manyears on a project and then realising at the end that you've built the wrong thing.
Well, a fluidity thing. But yes that’s related to risk. Being able to change direction at the drop of a hat. Also working with poor requirements which is a fairly common working condition in a lot of shops.
Agile is a risk management method.
You won't build things faster with agile in general. It's aim is to decrease the chances of spending 80 manyears on a project and then realising at the end that you've built the wrong thing.