A program could have all the advertising and tracking in the world and still be fully open source, as long as nothing stops you from creating a fork of it without that stuff.
[1] https://kagi.com
Of you could just use Brave.
Lots of online complaints about the founder's personal life/opinion but in terms of privacy, Brave is pretty good. Maybe not the best but pretty good for a solution that you don't need to fiddle with yourself.