Apart from the notification that there's a new version with AI, I can't say that I've noticed AI in Firefox at all. And I haven't even bothered (as far as I remember) going anywhere to try and turn it off.

That certainly doesn't feel remotely comparable to Chrome and Chredge.

Their blog post about it seems pretty clear, and it sounds good to me.

• First: Every product we build must give people agency in how it works. Privacy, data use, and AI must be clear and understandable. Controls must be simple. AI should always be a choice — something people can easily turn off. People should know why a feature works the way it does and what value they get from it.
• Second: our business model must align with trust. We will grow through transparent monetization that people recognize and value.
• Third: Firefox will grow from a browser into a broader ecosystem of trusted software. Firefox will remain our anchor. It will evolve into a modern AI browser and support a portfolio of new and trusted software additions.

And considering they're a non-profit, I don't see any particular reason to doubt their honesty.