Did they propose a specific alternative (non-extension) API?

Why would they? This is an issue put up on the "standards-position" repo. They requested a position on a proposed standard, and Mozilla gave it.

There’s one obvious alternative:

   fetch("https://api.openai.com/v1/chat/completions", { ... });

Right and that means people have to send their data to an external service.

Give it X months (or years??) and people will realize this is actually a privacy/data autonomy issue.

It's just dominated right now by the anti-AI/anti-technology sentiment in the west. That will gradually go away as more people use AI and robotics and realize how wrong they were about it.

>Right and that means people have to send their data to an external service.

Nothing in this proposal claims it has to be a local AI. That just happens to be the implementation by Chrome and Edge (for now at least, I'd imagine Google will eventually start moving this API towards hosted Gemini).

That's an important aspect of this that should really be part of the discussion on GitHub. But I've been told I'm not qualified to interject so I am not going to bother.

I will use WebLLM if I want something like this (with local AI guaranteed).

No, that’s not how this process usually happens.

Why would they need to?