Maybe give startpage a shot. They use Google results but it adds a privacy layer inbetween, and have the added privacy benefit of not being US-based compared to DDG.
Search quality is subjective, but in this case I mean better because it respects your search terms, quotes work for phrases, and organic results are enhanced with additional data sources like Stack Overflow [0].
I am the creator of Runnaroo.
1. Server rendered ads. They were there, you must have just missed them (it's on the SERP under the search bar). I don't have the search volume for context based ads (and none of the the available search ad networks are suitable), so the ads are just direct ads that display in rotation for a predetermined amount of time and do zero tracking (i.e. pay X and the ad is displayed for Y amount of time, win win for all).
2. Affiliate links. There is only one today, but I am testing it out to see if they are worth it.
3. Direct user monetization programs (i.e. Web Monetization protocol through Coil and the Brave publisher program). We are actually the first (and maybe still the only) search engine to integrate Web Monetization [0].
They say they won't change privacy policies etc., but we've often seen that such words don't mean anything a few years down the road, so I'm a bit skeptical.