Political corruption is like environmental radiation: a viable fix is never 'just get rid of political corruption'*. It's an environmental constant that needs to be handled by an effective approach.

That said, parent's size- and scope-iterative approach also helps with corruption, because corruption metastasizes in the time between {specification} and {deliverable}.

Shrink that, by tying incremental payments to working systems at smaller scales, and you shrink the blast radius for failure.

That said, there are myriad other problems the approach creates (encouraging architectures that won't scale to the final system, promoting duct taped features on top of an existing system, vendor-to-vendor transitions if the system builder changes, etc).

But on the whole, the pros outweigh the cons... for projects controlled by a political process (either public or private).

That's why military procurement has essentially landed on spiral development (i.e. iterative demonstrated risk burn-down) as a meta-framework.

* Limit political corruption, to the extent possible in a cost efficient manner, sure