I'd made a similarly titled post[1] a couple years back and I seriously don't know what kind of usage DuckDuckGo has right now. But I'd like to think that it is extensively used, at least in the developer community. And I strongly believe that people should start degoogling their lives at least slowly and gradually if its not possible to do it at once. If more people start using DDG, the search engine will improve and that least that one aspect of degoogling could be achieved to a certain extent.
[1] https://news.ycombinator.com/item?id=13284917
Most of the time I run the same search on Google the results are very similar for the top hits. But Google does seem to produce helpful results that are not exactly what I searched for more often.
DDG also skews heavily to US results which is a pain. Any Amazon links are always to .com and not the regional site. Just a general understanding of region specific results seems to be missing, and I end up qualifying searches with the country or town.