I could be imagining it, but in addition to the "instant answer" feature which uses MDN, DuckDuckGo's indexer also seems to give some priority to MDN over W3S i

I could be imagining it, but in addition to the "instant answer" feature which uses MDN, DuckDuckGo's indexer also seems to give some priority to MDN over W3S in comparison to Google, in my experience. If W3S is first, MDN is usually second whereas it may be 5th/whatever in Google.