Seems the playing field is a bit too open though, models are more fungible than the companies would hope so most of the current moat is brand based and seems like they're not ready to go all "Black Mirror" on us just yet.
same thing could've been said for search results, so at least that part is still "safe".
Remember when we got upset that Google was putting ads into image search [1]?
[1] http://www.ryanspoon.com/blog/2008/12/14/google-image-search... 2008
Ad technology is really old. They're just going to use the same proven tech that has a track record of creating billionaires: intersperse content with sponsored blocks.
The entire history of advertising before the web was companies estimating a dollar value on “awareness” when they couldn't measure direct referrals and every business in the world has gotten a lot better at measuring sales since then. It's not going to be transformative but if, say, Toyota got ChatGPT to say their vehicles were a better value than Ford's I suspect they'd be able to tell pretty quickly whether sales were improving relative to the competition and would pay well for that to continue.