Ads, sponsoring and SEO spam were also very unobtrusive for a while. A few decades passed and we have to sift trough all the garbage to find anything relevant in our searches, it's very likely that search engines will push harder and harder for these AI assistants while making finding organic content and authoritative sources even harder, resulting in it being nearly impossible to do research by yourself rather then trough an AI that has god knows what bias and perhaps subtle ad driven bias into it.

Take a look at a Google results page from 2009 and then from 2012 onwards. "Unobtrusive" is clearly a matter of opinion.

Sure, it’s subjective, but are you disagreeing that the new DDG chat button is unobtrusive?