[deleted] GrapheneOS doesn't recommend any particular search engine to my knowledge, DuckDuckGo is chosen by default because it doesn't use IP addresses and user data for targeted advertising, DuckDuckGo isn't really a search engine but a meta-engine that uses Microsoft Bing data behind a proxy.
Make comparisons and see what's right for you, you can also using more than one, in my experience, a flawless search engine is not available.