It has some nice features, like lenses, URL rewriting, and the ability to bump sites to the top.
I have a lens for programming. It shows only certain sites, like GitHub and Stack Exchange, and I enable it when appropriate.
For URL rewriting, I have Kagi set to rewrite URLs from Twitter and Reddit to my own self-hosted instances of Nitter [0] and Teddit [1], so that when I open a Kagi result that would've gone to twitter.com, it goes to nitter.mydomain.com, which lets me use Twitter without an account.
Lastly, I use the site bumping feature to move Wikipedia results to the top.