This is beside the point. Mozilla isn't pushing AI for the benefit of the browser or the users. It's in order to send a signal to investors. These days a company can't hold its head up in the financial marketplace without a loud and public commitment to AI.
Which investors? Mozilla make money from search engine placement on their browser. If their browser stinks, as it will if they keep pursuing these orthogonal projects, you think google will pay $400MM per year to be the default search engine on there?