I mean you can disagree with me, no problem with that. I would bet I have more knowledge about shipping major search engines than you do. I have worked extensively on both Bing and Google's search engines and now work on a third very large (O(exobytes)) search engine. 7-10 years is a really aggressive estimate IMO for something like Google or Bing, and I gave that estimate because I don't think people would believe my "realistic" estimate, even for Apple.

They could buy another search engine, but again getting Duck Duck Go to scale Google scale and relevance is still honestly a massive project.

I think they would risk losing people to Android phones as well. If tech-illiterate people suddenly start seeing that the "search engine" in Apple is terrible compared to Android they could lose customers. Better to just keep taking money, have a great search experience, and focus on other things.