DDG is just a proxy for Bing. Yes, let's degoogle our lives, but why not start using a free/libre metasearch engine (like Searx[0]), while you're at it?
I think nowadays they mix in some results from other search engines, but it started out as just Bing results. Doesn't change the point about it being just a proprietary interface to other proprietary search engines.
> We do use results from Bing. Our zero-click info and some other stuff we do, however, uses results from all over.[0]
They use Bing Ads, but I’m not sure if their actual search results are just proxied Bing results.