Are they serious? I just checked on my phone:

1) in chrome, click three dots 2) click settings 3) literally the first option in settings is "search engine" 4) click the new one. Done. Duck duck go is on the list

Wow their pr is really far reaching. Why do I need the duck duck go browser/app to use duck duck go?

Edit: unless this is about something else? Maybe for assistant? Or some other integration with the os?