Demand-aggregation allows the aggregator to extract the majority of the value. ChatGPT the app has the biggest presence, and therefore model improvements in Claude will only take you so far. Everyone is terrified of that. Cursor et al. have already demonstrated to model providers that it is possible to become commoditized. Therefore, almost all providers are seeking to push themselves closer to the user.

This kind of thing is pretty standard. Nobody wants to be a vendor on someone else's platform. Anthropic would likely not complain too much about you using z.ai in Claude Code. They would prefer that. They would prefer you use gpt-5.2-high in Claude Code. They would prefer you use llama-4-maverick in Claude Code.

Because regardless of how profitable inference is, if you're not the closest to the user, you're going to lose sooner or later.