Google could have done it and kind of tried, although they're AI sucks too much. I'm very surprised that OpenAI hasn't done this sooner as well. They're initial implementation of web search was sad. I don't mean to be super critical as I think generally OpenAI is very, very good at what they do, but they're initial browse the web was a giant hack that I would expect from an intern who isn't being given good guidance by their mentors.
Once mainstream engines start getting on par with Kagi, there's gonna be a massive wave of destruction and opportunity. I'm guessing there will be a lot of new pay walls popping up, and lots of access deals with the search engines. This will even further raise the barrier of entry for new search entrants, and will further fragment information access between the haves and have-nots.
I'm also cautiously optimistic though. We'll get there, but it's gonna be a bit shakey for a minute or two.