If people actually knew what percentage of tech demos, even by the biggest companies, were at least partially faked, they would be offended.
Unless I can actually use it myself and replicate results, I just assume that tech demos are complete crap.
Remember how maybe a year or two ago, Google showed a demo of a digital assistant independently calling and making an appointment for you with a hair dresser? It even added natural pauses, and "um"s and that sort of thing. If that was real, I think a lot of people would want it. Where is it? They already made it for the demo, right? So it seems like all they need to do is to sell access to it. Why would you put all that effort and make something and then not sell it? It's almost as if it never existed and the entire demo was fake.