Value in an AI stack sits in closing the 'diffusion gap' — the lag between what a model can do and what ordinary people actually adopt — which places the real engineering burden at the application/human boundary rather than at the raw model layer.
It relocates where reliability work belongs: adoption friction, workflow integration, and human trust are the bottleneck, not raw model capability. Teams that optimize only model capability ship capability that users never realize.
For any new capability (new model, new tool protocol, new modality), engineer for realized usage, not demonstrated capability; the gap is the product surface.
There is always a massive gap between what new technology is capable of and how ordinary human beings adopt and use it.
Founders must focus on building the application layer and bridging the human gap rather than just building raw technology.
Building applications on top of AI models requires closing the diffusion gap between what models can do and what people use them for.