|Think about Loose Coupling|
On the ground, in practice, in my experience, there isn't anything that Agile can accomplish that can't be accomplished without Agile. But it can also be a very useful toolset. It can be a burden if you have to fight too hard against coworkers who have too strong of a tendency to practice Agile soaked in too much Kool-Aid (that is, dogmatic attitudes will usually be a small problem but can also be a big pain).
It can be very useful to be able to get Agile adopted rather than work to get a whole laundry list of process changes adopted. And it can be particularly useful when you have to push back hard against Business/Product people who are aggressively impatient or demanding.
And I think there is some truth to the impression of Agile proponents that the various aspects of Agile work especially well when combined. And the principles of Agile can be useful for justifying improvements. But it is also my experience that refusing to "stray" from Agile is very harmful.
I think Agile makes a very good starting point for creating and maintaining a sane software development Process. You can also just study Agile and adopt parts of it or just use parts of it as inspiration to improve how your team works. But, in my experience, the teams that were based on Agile were closer to working well than the ones that weren't.
In reply to Re^2: Nobody Expects the Agile Imposition (Part VIII): Software Craftsmanship (useful)