I disagree, you're not conversing in good faith, because you're trying to win a pedantic argument that nobody else is engaging in. You see no way to "win" so you declare it bad faith.

The topic at hand is Mozilla adding AI into Firefox by default, and allowing users to turn it off if desired. So, optional, as you stated. The context that you're refusing to acknowledge however, because you're determined to win a pedantic argument rather than engage in a conversation, is that optional in this regard requires consent. Informed consent even. What does AI do to/for the end user? Why should they accept it to be on? What safeguards are in place? Unless they know this context, it should be off by default. Off by default is still optional, the user can still turn it on if they desire.

But you're hung up on the word optional and care more about the pedantry of that one word rather than the context that brought us all into this conversation in the first place.