No offence but I think you’re wrong. Apple could buy Duck Duck Go or roll their own and LOTS of people would find it good enough or do the first search on the default search engine.
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.
I'm not the typical iPhone owner (since I don't own one) but DDG is not "terrible" by any metric, especially compared to Google. I've used DDG nearly exclusively for a couple of years now, and every time I'm unhappy with the results and try the query on Google, it's no better there.
Apple can't compete with Google Search by buying Duck Duck Go as it relies on Microsoft Bing's shallow index. Bing (by market share) has failed to compete with Google search. To be good enough it's about scale not necessarily fancy names
Why would Apple buy Duck when they could just sign a deal directly with Microsoft? It’s not like Microsoft won’t know Apple bought Duck when it’s time to renew the contract anyways.