DDG is quite good in regular search. I like their commitment to privacy and so switched my default search engine to DDG. But I noticed more and more that I use google maps almost as much search. I search for places and directions on maps end up going to google a lot. That is brilliance of Google. They built search verticals and so its tough to not use them. If only DDG could do something about that.
Problem with OSM is that it's nowhere near as complete as Google Maps, and I don't see it growing the way Wikipedia did (contributing to Wikipedia is much easier than contributing to OSM)