I don't think that will ever happen. All you need is a trivial browser extension with a locally run, very primite LLM, that takes the output of the commercial LLM, and removes all advertisement. And adBlocker AI, so to speak.

Yes, there will be people not using adblockers just as there are people today. But no adblocker ever was able to remove SEO spam from googles website, all they did was hiding obvious adds. They didn't improve the search experience.