I would differentiate between iterative development and incremental development.

Incremental development is like panting a picture line by line like a printer where you add new pieces to the final result without affecting old pieces.

Iterative is where you do the big brush strokes first and then add more and more detail dependent on what to learn from each previous brush strokes. You can also stop at any time when you think that the final result is good enough.

If you are making a new type of system and don’t know what issues will come up and what customers will value (highly complex environment) iterative is the thing to do.

But if you have a very predictable environment and you are implementing a standard or a very well specified system (van be highly complicated yet not very complex), you might as will do incremental development.

Roughly speaking though as there is of course no perfect specification which is not the final implementation so there are always learnings so there is always some iterative parts of it.