Recently, I read on another HN thread that Kagi uses Google to build its index. If that's the case, the only way Kagi appears better than Google is that it doesn't show ads. Not sure, if my understanding is correct or not.
kagi allows you to downrank or even ban or boost certain websites so that when you serach, if there is a result from that website, it'll be downranked or boosted based on what you set up. It also automatically downranks websites that use shady ad trackers. They are slowly building their 'crawler' too but it's more nuanced regarding how they do this