There isn’t a free alternative that works as well, unfortunately. Bing not only has many of the same issues, but has worse results. Since DuckDuckGo makes use of Bing’s API for its results, in addition to lacking features such as date range searches, it is still a step down in terms of the quality of one’s search results. Having switched to Firefox due to Google’s efforts to make unilateral, self-serving changes to Chromium, I’d be only too glad to switch search providers if an alternative provider had a similar number of accurate results.