I tried Kagi for the free trial and I do not share your enthusiasm or positive experiences.
I really wanted it to be great, but for the things I search (I am searching mostly extremely technical, and domain specific things), I found myself doing the same search on Google by prefixing !g, and Google nailed it so much more a lot of times. So much so that I didn't even finish the free trial, but went back to Google as my default in the browser.
Maybe I'll give it another go in a few months, but for now it's not for me.