GPT-3 conspiracy website. The readership won't know the difference.
GPT-3 Bongard puzzles. (If this were possible I would be impressed enough to think AGI is soon plausible)
GPT-3 recipe blog. Just take open-source recipes from somewhere and give some saccharine prompt about your grandma.
GPT-3 disinformation bot. Sow FUD, influence elections for the low. (Would be unsurprised if this is already being done)
GPT-3 crypto pump bot. Post positive sentiment comments about your crypto of choice
GPT-3 idea generating bot bot. Think of new applications for GPT-3
GPT-3 grimoire. Unlock the secrets of the adepts with the secrets of the adepts
GPT-3 post-modern novel. Too easy
GPT-3 Sokal Affair, Bogdanov affair
GPT-3 Erowid trip reports. Describe your imaginary drug and get the trip reports.
GPT-3 trashy romantic novel
GPT-3 Zen koans. Penetrate your thick skull with AI to experience kensho
GPT-3 writer's block unsticking. Feed where you're at and then use the output to trigger ideas where to go next