I've had a different experience.

It's been successfully bringing me the correct stackoverflow results I would expect when I need to search.

I really like DuckDuckGo, but I'm not super happy to get Taylor Swift results when searching for iOS/Swift related things :(

The fact that DuckDuckGo embed a SO snippet of the search query you entered makes it very useful for me.

In my experience it's getting better every few months. A year ago compared to now feels like it's a different search engine and I find new stuff every day, for example, vim cheat sheet

I also thought that months ago, but it seems much better now.

Plus, I'm really starting to like the bangs, which allow you to search language-specific docs directly without any setup.