I think most people in the tech sector and especially driving the AI hype have absolutely no clue how difficult it is to implement change in complex organisations. There are a bunch of technical reasons but half the reasons are not even technical - social, legal, etc. You have to shift the practices of humans and they have incredible inertia. Like decade level change response period. And during the change period they are less productive. Expect a decade type period before "productivity" impact manifests and even then it won't really be measurable directly because people will be doing different things.