I have used brave search which was really good I really liked the ai search although i moved away from it after seeing how bad google ai search was (saying things like its a good idea to eat rocks due to not being able to recognise satire) and I managed to get brave to do the same thing with a different onion article so i dont really trust any ai search now. At the moment I use searx it's incredibly private especially if you are willing to self host (I am not) and you have so much customisation you can use any search index so you don't have to worry about bad results.
Qwant also seams really good although I haven't tried it, same with ecosia especially if you like planting trees although I use an ad blocker so that doesn't work for me.
Imo there are so many great free browsers it's not really worth paying for a browser.
I also don't recommend duck duck since it used to have a tracking deal with Microsoft. It doesn't have it anymore but I think it's enough to lose faith in it.