From Mark Surman at the Mozilla blog:
I know that losing Google’s paid search money is basically all of Mozilla’s income, but ads and AI aren’t the answer. I would guess that anyone using Mozilla is blocking ads, and AI in a browser is just not worth paying for? I mean Mozilla’s current AI summarizes web pages, but is that a money maker? I mean really? AI costs money to run so you have to pay for it, and I just haven’t seen where AI in a web browser is going to make Mozilla enough money to survive.
And Mozilla needs to survive as there is Chrome/Chromium which you can’t trust cause it is Google, Safari, which is Apple so they will never allow Mozilla’s level of customization, and Mozilla, which makes no money.