Serving requests where every user has their own set of self-updating weights will absolutely murder whatever minimal margin the AI providers have today

Who says the weights have to be duplicated in their entirety? Even that will likely be worth it.

Imagine an OpenAI owning the ERP and CRM databases and workflows of a big chunk of the Fortune 500. Their typical customer's employee headcount might be 10% of what it once was, and OpenAI might capture 25% of the resulting savings. The contracts are signed in the same hemoglobin-based ink that Larry Ellison uses.