I use DDG on Android and it works pretty well there. I also saw this line in the article and it's somewhat of a stretch to call DDG either a "major" browser (as you point out) or a "non-Chromium browser". My understanding is it uses the browser engine bundled with the OS on Android/iOS/Mac/Windows and it isn't available for Linux.
The wikipedia article on it says:
> The core browser functionality is the WebView component provided by the operating system. This means the browser engine is Blink on Android and Windows, and WebKit on iOS and macOS.
The wikipedia article on it says:
> The core browser functionality is the WebView component provided by the operating system. This means the browser engine is Blink on Android and Windows, and WebKit on iOS and macOS.