I know of at least one startup that claimed to use AI (including having AI in the company name), but in actuality humans did nearly all of the work. Hoped that once they got enough customers (and supposedly "proved the concept"), they could figure out how to use AI instead. I bet this is/was somewhat common.

I also see many (particularly "legacy") products say they're "AI-driven" or "powered by AI", when in actuality one minor feature uses some AI, even in the broadest sense.