I don't want to sound like an astroturfer but bing results have actually gotten much better too. Though search is a big field and something I wouldn't mind mozilla getting into too.
This is an oft repeated misconception, their results come from multiple sources. (ddg user since ~2013, and there were times when they did heavily favor yandex or bing usually, but these days the sources are much more varied, and they also have their own crawler called duckbot I think)