The do have some use. Take for example the AI images of the pope wearing luxury brands that someone made about last year. They clearly wanted to make it as a joke, not to purposefully misinform people, and as long as everybody is in on the joke then I see no issue with that. But some people who weren't aware of current AIgen capabilities took it as real and an AI tag would have avoided the discussion of "has AI art gone too far" while still allowing that person to make their joke.