They’re all based on others indexes to be honest so there isn’t really one.

DuckDuckGo is Bing, Startpage is Google, Kagi is seemingly a mishmash of a bunch of search engines (including the Russian owned Yandex) Brave is independent but owned and run by assholes so that isn’t much better.

Personally I like Kagi enough and it’s independent enough for me to pay for it.

Such as?

Still uses Google as an index so you’re just giving them money indirectly.