More features (lenses, explicit personalization), more results (it’s bing + google indexes + extra), and better results (IMO).
> I really don't like that Kagi requires you to have an account.
Many don’t, but you lose a lot of what makes it so much better without it.
> They can then associate all of your searches to that account
Yes, but then the rationale is that they are so expensive, so they don’t need to do shady shit like that. Currently, they don’t even save your history which is planned as an optional feature for later (so you can look into your own history).