Also, _come on_; if someone gives up after one search term, which also includes advanced site-restricting syntax, there's no way they'd be able to operate youtube-dl anyway: https://duckduckgo.com/?q=youtube-dl&ia=web
You can still access it from the results via other sites, like github and wikipedia (which even makes the real website pop up in the info square, funnily enough), but the search results themselves do not contain any links to the main website.
This seems like an oversimplification of things you don't know.
That's pretty easy to check for yourself, usually whenever something does not show up on Bing it won't on DDG either. A good example of that was when the "tank man" picture disappeared from Bing and the exact same thing happened on DDG.
That relationship has reportedly been "paused":
https://www.protocol.com/bulletins/duckduckgo-yandex-ukraine