I don't like that Kagi requires a login. I understand why they have a login, otherwise they couldn't charge for their services.
But the inability to perform an anonymous search is a fail for me. I fear that, in the long run, they will change their ToS and collect/sell my search history – with that history connected to me personally – and this rules them completely out from where I stand.
This lesson in trust was hard learned; I won't forget it.