So it looks like the underlying plugin basically just checks if there is a disclosure on the steam store page.

So... it isn't useless. But the vast majority of things people are buying on itch aren't on Steam and would still be the wild west. And I am always wary of any of these plugins because you never know where it will go. Could EASILY become "This is woke so it must be AI so let's prevent people from buying it". And... there is also always the concern over what data you are giving the extension access to and how much you trust the extension writers.