They have sent out direct mailers that basically equated to a customer list leak; also I'd take a peek at the wikipedia entry about their business model, which mentions some stuff that isn't the most savory:
... Brave earns revenue from ads by taking a 15% cut of publisher ads and a 30% cut of user ads. User ads are notification-style pop-ups, while publisher ads are viewed on or in association with publisher content.
On 6 June 2020, a Twitter user pointed out that Brave inserts affiliate referral codes when users navigate to Binance
In regards to the mailers, they messed up and passed blame,
In this process, our EDDM vendor made a significant mistake by not excluding names, but instead including names before addresses, resulting in the distribution of personalized mailers.
I would remove Qwant from this list, because they share your data with Bing, their privacy policy have contradicting statements and include:
Qwant may transfer to this partner the following pseudonymous data related to your query:
– The keywords of the search;
– Information about the browser you are using (the User Agent);
– The first three bytes of your IP address;
– The approximate geographical area from which the search originated, at the level of a region or city;
– The salt hash generated from your IP address, your User Agent and a salt that changes at the latest every 3 months;
– A random token generated by Qwant.
..Qwant may also collect and transfer to this partner your full IP address.
This processing is in the legitimate interest of Microsoft Ireland Operations Limited (article 6.1.f) to secure and make its services more reliable.
This data is transferred to this partner within the European Union, and may be retained in accordance with Bing’s Privacy Policy for a maximum period of 18 months.
I can't recommend a self hosted SearXNG instance enough.
DDG uses Bing as a search backend last I checked, and the founder/CEO is spoke in favour of censoring search results that don't match with his worldview.
As others have stated, you are mixing search engines with metasearch engines here. If you employ browser isolation and obscure your IP address, you can be anonymous with any engine.
Yacy has potential, and I run an instance. It relies on us operators to index sites. You will find results to be incomplete in many areas, but it can be great for researching controversial topics. When I want uncensored and not manipulated results, I also use Yandex.com and Brave.
searx and searxng are not search engines, and searx is more private (searxng collects info from users, which searx never wanted to). AFAIK duckduckgo is neither a search engine on its own, it uses blink...
To tell the truth, only yacy and sightnet have own index(database).
Others are meta-search engines. They work like proxy. It's called meta search. (https://en.wikipedia.org/wiki/Metasearch_engine)