“We do not believe an LLM API belongs in the web platform.”
Chrome wants every webpage to be able to call into Gemini Nano on your machine. Mozilla, correctly, says no. The Prompt API would make the web depend on a specific model from a specific company that ships with the browser. That is the opposite of what the open web is supposed to be. Mozilla holds two percent of the market and will lose this fight, but the position is right.