Agile is the reason requirements are allowed to change. Non-agile is not changing the requirements, and continuing to build the wrong thing.
But it's not that binary. "Agile" is the reason requirements are allowed to change constantly. At worst, it can be like trying to steer down the freeway by slamming the steering wheel from one extreme to the other. And pure waterfall is also blatantly unworkable.
The real question is, at what rate do you allow changes to be made to the specification/requirements? How much dampening do you apply? And maybe under that, there's another question: How fast can you respond to the real world, and still maintain a coherent direction? The faster the better, but don't try to respond faster than you can maintain coherence.
Changing requirements is like fast food, people don't eat it because they need the calories they eat it because it is hard not to.
And agile doesn't make you respond to change quicker, it makes it slower since it is done in 2 weeks sprints. Normally a team could adapt the moment new information comes up, strict adherence to scrum agile would push that for the next sprint.
Agile does make scheduling new changes effortless though, encouraging new changes to be made all the time, but it doesn't make the team react quickly to those changes and nor does it remove the total cost of a change. I don't think that is a good thing to encourage, in such a system no wonder people get used to changing things all the time so nobody really knows what things are supposed to be.
Agile means you can respond to a change in "what's most important" more quickly. You can't respond to everything more quickly, though, because you can't do everything at once.
But it's not that binary. "Agile" is the reason requirements are allowed to change constantly. At worst, it can be like trying to steer down the freeway by slamming the steering wheel from one extreme to the other. And pure waterfall is also blatantly unworkable.
The real question is, at what rate do you allow changes to be made to the specification/requirements? How much dampening do you apply? And maybe under that, there's another question: How fast can you respond to the real world, and still maintain a coherent direction? The faster the better, but don't try to respond faster than you can maintain coherence.