It's just you. Fable 5 is consistently better than Opus 4.8 at literally every single level, for me. (I always use both at xhigh, for reference.) I could go down a laundry list of various issues I have with Opus that I don't have with Fable. For me, Opus 4.8 < GPT-5.6 Sol < Fable 5.
Plus Fable is way less annoying to talk to than Opus 4.8. Opus 4.8's writing style is absolutely insufferable. Fable has some of the same quirks but it's way less bad.
This would seem to lead to absurd implications. What if in, say, 20 years, an AI is able to independently prove nearly everything important in under an hour, including the Riemann hypothesis, with no contamination from other proofs? (Let's say it's also free to write and run arbitrary code, as well.)
Whether it's 5, 10, 20, 50 years, obviously the takeaway cannot be "something had gone terribly wrong". The takeaway would be the smartest humans were never close to the theoretical intelligence and wisdom ceiling and never could've been. This will one day seem obvious in retrospect. There's no reason evolution by natural selection would've landed any species near such a ceiling.
Hot take: even GPT-3 was not a parrot. Skeptics have never properly internalized that the fundamental operation is basically irrelevant to the gestalt. Humans are not parrots yet neurons likely also largely operate via predictive processing.
You can use that retroactive logic about any hard problem though. Unsolved murder cases, math, theoretical physics.
If tons of smart humans try for years and fail and then an LLM tries for a few weeks or hours and succeeds, the implications are clear. And these are by far the dumbest LLMs will ever be.
I don't know why you're saying this, given this is not sycophancy and instead is an actual example of Claude Fable finding a real counterexample. I would get it if the mathematician had in fact posted something untrue or crankish, but he posted something true.
Frontier models have solved several major open problems in mathematics in the past few months, so this should not be a huge shock. "Anti-AI psychosis" will probably grow to outcompete AI psychosis by year's end.
The interesting thing about using Claude Fable 5 is it's nearly as irritatingly sycophantic as past Claudes while genuinely being smarter than the previous models. So you get a kind of yo-yoing of it glazing you as a creative genius and disappointedly revealing to you that your ideas are bad and dumb.
No offense but that seems like a...not good use of money. For the $100/month or $200/month tier you'd get way more out of Claude Fable 5, which is definitely a better model than K3 for coding.
Oh yeah, I've noticed the same, for sure. But that's basically what I was expecting. The best model is not necessarily always going to be the most cost-effective/sensible model for a particular use case.
Fable-class models will probably be cheaper for Anthropic to serve within the year, though. And rumors are GPT-6 is of similar size and intelligence to Fable and may come out within the next few months. OpenAI models tend to give you more bang for your buck, probably in part due to OpenAI being able to throw more capital and compute around on top of being particularly willing to loss-lead to stay competitive with Anthropic.
At this point I barely put any value in any of the benchmarks. I just use the models for coding (and related things like software product design/planning/ideation/etc.) tasks and judge them subjectively, and also see how others judge them subjectively on HN and Twitter.
- I agree that trying to hamfist a poorly-engineered game-like rendering engine into Claude Code was not wise - hence my agreement in my initial post that "Claude Code is seemingly currently not very well-engineered".
- All of the stuff unrelated to rendering/display is the complicated stuff I was referring to. It's actually not easy to get an agentic harness (even one with, say, the simplest TUI imaginable) to work as well as Claude Code and Codex do.
- I included "necessarily has to be" to separate the two - it does not necessarily need to have a weird buggy rendering engine thing, it does necessarily need to have lots of careful agentic massaging.
- I do not understand how the implication "writing a game engine is easier than writing Claude Code" could have been drawn from my reply.
I agree Claude Code is seemingly (currently) not very well-engineered but I think you may be moderately underestimating how complicated it is/necessarily has to be.
I promise your post was already downvoted when I saw it. It is possible some people upvoted it afterwards, changing the net karma.
It is possible you were not intentionally choosing to use an LLM to write/modify your posts, but they largely read like LLM output. The tool you're using may use an LLM and may be rewriting significant portions of your text.
Plus Fable is way less annoying to talk to than Opus 4.8. Opus 4.8's writing style is absolutely insufferable. Fable has some of the same quirks but it's way less bad.