Why Defend the Frontier

AI capabilities now exceed what I need from them

I suspect we’re at or very close to the top of the bubble in AI valuation for frontier labs. The signal for that is simple: I don’t know anyone using Fable, despite everyone espousing its power.

Much ink has already been spilled about the headwind that open-weight models will pose to frontier labs. The labs’ response has always been simple: people will pay for the gap to get to the frontier, and being at the frontier will allow them to build stronger models at every point on the cost/performance curve.

I bought this logic for a long time-every time I tried out open-weight models, I could still feel a performance gap between them and the closed-weight frontier. That gap kept me paying for (several) max plans. But in the last three months, my behavior has changed substantially. Not by switching to an open-weight model (Kimi K3 still lags behind what I need out of it), but because of how the cost/performance curve has shifted inside each of the frontier labs’ offerings.

• I mostly use Opus 4.8 instead of Opus 5 because it drains my quota less quickly, and I can’t see any gap in performance.
• I mostly use Terra on high because it performs simple tasks more quickly and cheaply than Sol.
• I think Fable is incredible, but I only use it on the tasks that need it, and even then only overnight and if I have some slack in my weekly quotas.

In short, AI labs now build budget products that are (mostly) capable of the tasks I need done, so I reach for the true frontier less and less often. Now, I’m just a humble SWE—perhaps it will take a year or two for the best security engineers or Terence Tao to feel similarly. But in my job—complex systems engineering—AI capabilities now outstrip my demand for them, and I don’t see why that would not be (eventually) true in other fields.

Now I want to draw a critical distinction - AI cannot do my job yet. I’d love to see someone try to replace me with AI - it would be hilarious to see the mess they get into: even Fable still routinely suggests terrible architectures and spins confidently on bogus assumptions. I’m not claiming AI can do my job, I’m claiming that AI can do a good enough job at most of the tasks I want AI to do in my job - debugging, drafting designs, reviewing PRs, and writing code - such that I don’t need to pay for the frontier (in quota, but the logic holds for dollars).

Don’t take my word for it: ask your most AI-pilled friends. Does anyone use Fable frequently? Does anyone find the 1.5x cost of Opus 5 vs. 4.8 worth it?

If the frontier moves out of reach from human necessity, the frontier could still be defensible, but it will make no economic sense to defend it.