We want "normal" users to use Firefox, not to push it to a smaller niche with more force. Even though I don't like or use this "AI thingy", it should be equally easy to use and equally easy to disable.
If Firefox can provide a more anonymized gate to these providers and guarantee that prompts are not used for training, this would be a net win for people who want to use AI but doesn't know better, i.e. the "normal" users.
That's how normal users stay on chrome while your users leave firefox. That's how you get no users at all.