This is so wrong it's laughable. Please provide proof if this ridiculousness.
https://en.wikipedia.org/wiki/DuckDuckGo
https://web.archive.org/web/20150124074006/https://duck.co/h...
https://www.theregister.co.uk/AMP/2017/08/15/bing_microsoft_...
If bing offers up the best results most of the time DDG will, as a result, offer up bing results most of the time. "Best results" easily determinable even with DDG privacy constraints.
They're definitely doing some cool stuff at DDG and its certainly a hell of a lot more than "a wrapper around bing." I just don't think expanding their own index infrastructure is something feasible for them right now.
“Just a wrapper” is misleading, but DDG returns bing results at least some of the time.