For the most time, the DuckDuckGo .onion was a v2 onion, even when Tor Project announced that they’ll be deprecated soon because they’re insecure and won’t do a lot for your privacy these days. Yet DuckDuckGo didn’t (or didn’t want to) update to v3 until the last moment. Which tell us that they’re not very interested in our privacy.
And, if you use its .onion with JS disable, it will redirect you to html.duckduckgo.com (clearnet)
A sweet MITM, tell DuckDuckGo what you’re searching in other websites by saving a few clicks. This feature is a MITM and useless because browsers can already add multiple search engines and in the case of Pale Moon and Firejunk you can right click an input and click “add keyword for this search” and you can have a bang without telling DuckDuckGo where you’re going