Give them a political bent - that's probably what the state actors are trying to productionize right now. Target posts with a sentiment that disagrees with yours, then make the bots follow those users and inundate them with replies wherever they go. Hell, even brands might step in and start doing it.
What's the value of a social network when 25% or more of the comments are from GPT-3 bots?
GPT-3 doesn't need to know anything at all for it to have a very noticeable impact on the web and social media.