(~ Facebook is an ad machine pretending to be a social network, Google is an ad machine pretending to be search engine, etc.)
...but, "advertising" is really just an effort to match supply and demand
diffusion of innovation
whenever a sale happens, it's a good thing; value is created; both sides benefit
what people don't like is... ads that don't work
seeing ads that are not directly relevant (or ones that try to generate demand, but fail at it)
...which is seen as a cost (distraction from whatever else they were consuming)
google's approach is "more benign" because many searches have purchase intent ("I am looking for an X") or demand/need/problem intent ("how do I solve X issue?")
facebook/instagram/etc. are more about "demand generation", "things you didn't know you needed" based on demographic profiles and interests
chatGPT likely is getting a lot of demand/need/problem intent, some purchase intent, and some profile info
will likely become a major platform for "advertising", but it may take a more subtle (and maybe less "annoying" form)
the "obvious" would be gmail-esque sidebar ads
people would likely tolerate
the "sneaky" would be "product placement" injected in answers
ex. asking about controlling blood insuling levels, it injects a recommendation for wegovy
(this would likely get a LOT of pushback; people would lose trust and stop using it)