Firefox for Android is great, and after some initial teething problems, it’s been solid for a long time.

I remember seeing on reddit a story about a guy who created something and I think suggested DDG stole some of his work and packaged it up as their own. I cannot find it anymore, but remember seeing it at the time and it seemed convincing (even though I was using DDG search and was a fan of their work). I still use them, but not for everything and I remain skeptical. FF is open source, and has been pretty trustworthy for a long time imho.