[lossolo]

In the context of our conversation and what OP wrote, there has been no breakthrough since around 2018. What you're seeing is the harvesting of all low-hanging fruit from a tree that was discovered years ago. But fruit is almost gone. All top models perform at almost the same level. All the "agents" and "reasoning models" are just products of training data.

I wrote more about it here:

https://news.ycombinator.com/item?id=44426993

You may also be interested in this article, that goes into details even more:

https://blog.jxmo.io/p/there-are-no-new-ideas-in-ai-only

[sothatsit]

This "all breakthroughs are old" argument is very unsatisfying. It reminds me of when people would describe LLMs as being "just big math functions". It is technically correct, but it misses the point.

AI researchers spent years figuring out how to apply RL to LLMs without degrading their general capabilities. That's the breakthrough. Not the existence of RL, but making it work for LLMs specifically. Saying "it's just RL, we've known about that for ages" does not acknowledge the work that went into this.

Similarly, using the fact that new breakthroughs look like old research ideas is not particularly good evidence that we are going to head into a winter. First, what are the limits of RL, really? Will we just get models that are highly performant at narrow tasks? Or will the skills we train LLMs for generalise? What's the limit? This is still an open question. RL for narrow domains like Chess yielded superhuman results, and I am interested to see how far we will get with it for LLMs.

This also ignores active research that has been yielding great results, such as AlphaEvolve. This isn't a new idea either, but does that really matter? They figured out how to apply evolutionary algorithms with LLMs to improve code. So, there's another idea to add to your list of old ideas. What's to say there aren't more old ideas that will pop up when people figure out how to apply them?

Maybe we will add a search layer with MCTS on top of LLMs to allow progress on really large math problems by breaking them down into a graph of sub-problems. That wouldn't be a new idea either. Or we'll figure out how to train better reranking algorithms to sort our training data, to get better performance. That wouldn't be new either! Or we'll just develop more and better tools for LLMs to call. There's going to be a limit at some point, but I am not convinced by your argument that we have reached peak LLM.

[lossolo]

I understand your argument. The recipe that finally let RLHF + SFT work without strip mining base knowledge was real R&D, and GPT 4 class models wouldn’t feel so "chatty but competent" without it. I just still see ceiling effects that make the whole effort look more like climbing a very tall tree than building a Saturn V.

GPT 4.1 is marketed as a "major improvement" but under the hood it’s still the KL-regularised PPO loop OpenAI first stabilized in 2022 only with a longer context window and a lot more GPUs for reward model inference.

They retired GPT 4.5 after five months and told developers to fall back to 4.1. The public story is "cost to serve” not breakthroughs left on the table. When you sunset your latest flagship because the economics don’t close, that’s not a moon shot trajectory, it’s weight shaving on a treehouse.

Stanford’s 2025 AI-Index shows that model to model spreads on MMLU, HumanEval, and GSM8K have collapsed to low single digits, performance curves are flattening exactly where compute curves are exploding. A fresh MIT-CSAIL paper modelling "Bayes slowdown" makes the same point mathematically: every extra order of magnitude of FLOPs is buying less accuracy than the one before.[1]

A survey published last week[2] catalogs the 2025 state of RLHF/RLAIF: reward hacking, preference data scarcity, and training instability remain open problems, just mitigated by ever heavier regularisation and bigger human in the loop funnels. If our alignment patch still needs a small army of labelers and a KL muzzle to keep the model from self lobotomising calling it "solved" feels optimistic.

Scale, fancy sampling tricks, and patched up RL got us to the leafy top so chatbots that can code and debate decently. But the same reports above show the branches bending under compute cost, data saturation, and alignment tax. Until we swap out the propulsion system so new architectures, richer memory, or learning paradigms that add information instead of reweighting it we’re in danger of planting a flag on a treetop and mistaking it for Mare Tranquillitatis.

Happy to climb higher together friend but I’m still packing a parachute, not a space suit.

1. https://arxiv.org/html/2507.07931v1

2. https://arxiv.org/html/2507.04136v1