Upvote this question, it's pretty relevant to the issue of whether this would have been good for Apple (no, it would not have been)
DDG is my default search on mobile, but half the time I end up back on Google. Google is better at guessing exactly what I want and giving that content fast, such as the weather, people always ask answers, or quick facts about things that saves me from loading the site underneath the result.
But sometimes I know exactly what I want and Google won't give it to me - because it decided I want something else.
That's where a well built query can work better on DDG. However... DDG is more susceptible to backlink spamming and old school SEO techniques to rank content near the top. So depending on the people behind the search results, some queries are fine and some can still be garbage.
Also for image and video search Google is top.