The problem with "Agile" is that it only solves a small part of the problem.  If the objective is to increase throughput in the delivery process, then a much more robust (and automated) approach is called for.  I suggest the book Lean Enterprise by Jez Humble as a good primer. 

The problem for most places that try Agile is they treat it like a noun instead of an adjective.

Agility is a goal, not a method. Agile is descriptive in that it describes the things that should be valued and gives some principles to follow, but all in all it completely stays out of how to do it.  That causes frustration for management and those who want a manual.

I personally follow a set of principles called Modern Agile:

• Make Safety a Prerequisite
• Experiment and learn Rapidly
• Make People Awesome (or at least find ways to help them become awesome in achieving their goals)
• Deliver Value Continuously

I personally feel that you can't do the last if you're not doing the other three with consistency. Making people awesome isn't forcing anyone to meet your definition of awesome, it's helping them identify what they need to be awesome or helping them to realize they can be awesome. (That includes both the end user and the people on the team)

This is where frameworks like Scrum, XP, Lean and others come in as a way to achieve agility. The problem is that most people treat them as the end rather than as a beginning of their journey to Agility.

I'm a certified Scrum Master through Scrum.org and one of the first thing I learned in studying for the test is that  there are way too many people who want to treat Scrum like stone tablets from on high rather than as a starting point. That gets completely away from experimenting and learning rapidly. If you aren't using your retrospectives to identify what you can do better and then working very hard to do it better, you've already missed the point.