I compiled a list of search engines that use their own indexes for organic results: https://seirdy.one/2021/03/10/search-engines-with-own-indexes.html

I’ll probably post a big update to that article at some point that compares if/how some of the listed engines process structured data (RDFa, microdata, JSON-LD, microformats 1/2, open graph metadata, POSH).

I typically use a Searx/SearxNG instance that mixes Google, Bing, and Bing-derivatives (e.g. DDG) with other indexes: Petal, Mojeek, Gigablast, and Qwant (Qwant mixes its own results with Bing’s). Petal, Gigablast, and Mojeek have been quite helpful for discovering new content; however, I wouldn’t use Petal directly due to privacy concerns. Using it through a Searx proxy you trust more seems alright.

If I know a query will give me an instant answer I want to use, I’ll use DDG.