There are instruction on how to use DDG from within Safari, but I can’t change my search engine settings to DDG in Safari like the instructions say. How the heck are you seeing the tracking cookies blocked?
This ability to specify a specific search engine is a capability present every web browser marketed in the US and is packaged as a component of the operating system. It was the subject of antitrust litigation several decades ago to prevent monopolies on information acquisition. The EU also went through this wrestling match with Microsoft and the IE browser. This has nothing to do with the Duck browser app for IOS that I'm giving a test drive.