AI Impacts has been building a collection somewhat like this:
Gwern recently had a popular post that was exactly that kind of thing: https://www.gwern.net/Clippy
Amusingly, I was writing https://www.lesswrong.com/posts/BkHRpF2cafyaoWxaT/believable-near-term-ai-disaster at the same time as you were posting the question, based on an earlier brainstorming exploration at https://www.lesswrong.com/posts/KTbGuLTnycA6wKBza/ .
All the stories I've read, even Gwern's recent one feel surprisingly abstract. To me the obvious, very concrete story for an intelligence explosion looks like this:
Obviously Codex isn't nearly good enough to do this and you would need the benchmarks to include very difficult tasks, so that as it starts to take off it still has room for improvement. But I don't see why it would require a different kind of model.
I was wondering if anyone’s compiled a list of posts which give a concrete description (with scenario-specific details) of a hypothetical future where humanity suffers an X or S scale disaster due to AGI takeover. If such a list does not already exist (or does exist but needs to be updated), please put links to specific posts of this kind in the comments!